Rhubarb Elderflower Cake
By Emma
Certified Culinary Professional
•
Recipe tested & approved
Light fluffy cake with rhubarb jam and elderflower glaze. Soft whipped egg whites folded carefully for that airy crumb. Rhubarb cooked down with lemon juice until thickened, gelatin added to hold just right. Elderflower syrup adds floral aroma to batter and glaze. Bake until toothpick comes out clean with golden edges. Chill jam well for spreadable texture. Sweet but tart balance. Fragrant, moist, delicate. Can swap cream with coconut milk for dairy-free. Use agar agar instead of gelatin for vegan. Keep glaze runny enough to drizzle yet thick to coat. Serve chilled under cake dome to maintain freshness.
Prep:
40 min
Cook:
35 min
Total:
Servings:
12 servings
#French-inspired
#vegetarian
#vegan option
#baking tips
#seasonal desserts
Fluffy but sturdy cake, crumb light as clouds yet holds jam without sinking. Elderflower syrup lifts simple flavors – a hint floral, subtle but striking. Using separate egg whites phases, beating technique crucial – not a beginner’s sleight. The rhubarb jam that’s more a compote with firm set, gives balance to sweetness, acidity extra punch. Glaze shiny, sticky, sweet with that signature elderflower whisper; looks simple but is layers of love really. Fiddly sometimes but every step rewards patience. Tried it over years, tweaks here and there to nail texture and timing. Armed with that, kitchen trust grows. A gentle bake, slow cooling, and delicate folding makes all difference.
Ingredients
- 120 g all-purpose flour, sifted (about 3/4 cup plus 1 tbsp)
- 11 ml baking powder (about 2 1/4 tsp)
- 1 ml salt (1/4 tsp)
- 3 large eggs, separated and at room temperature
- 100 g granulated sugar (just under 1/2 cup plus 1 tbsp), divided
- 130 ml heavy cream 35% (about 1/2 plus 1 tbsp cup), can sub coconut milk for non-dairy
- 15 ml elderflower syrup (1 tbsp), plus extra for glaze
- 5 ml powdered gelatin (1 tsp), or 8 ml agar agar powder for vegan
- 15 ml cold water (1 tbsp)
- 300 g fresh or frozen rhubarb, diced (about 2 1/2 cups)
- 150 g granulated sugar (3/4 cup plus 1 tbsp)
- 20 ml fresh lemon juice (about 1 tbsp plus 1 tsp)
- 100 g powdered sugar (3/4 cup) for glaze
- 30 ml elderflower syrup (2 tbsp) for glaze
- Optional edible flowers for garnish
About the ingredients
Adjusted a bit smaller flour quantity for finer crumb; extra tablespoon beyond original approximated. Switched baking powder measurement slightly up for better rise. Gelatin powder stays, but suggesting agar agar for vegan twist. Cream optional, canned coconut milk works with same ratio though flavor shifts; coconut adds body but watch whipping power lost. Elderflower syrup key, but can improvise with honey plus lemon zest for floral hints. Dividing sugar between yolks and whites critical to get meringue firm but moist. When folded, no rush; one careless fold and volume collapses. Rhubarb: fresh or frozen OK but frozen needs draining; extra water dilutes jam badly unless boiled longer. Pan ungreased; parchment only to let cake grip edge for rise stability. Keeps cake from sliding – trust that.
Method
Cake
- Set oven rack mid-position. Heat oven to 180 C (350 F). Line 20 cm springform pan base with parchment only; no butter. Flour avoided here to keep crust tender; trust parchment.
- Sift flour, baking powder, salt together. Dry ingredients separate for even distribution; no lumps.
- Whisk egg yolks with 55 g sugar, cream, elderflower syrup till totally smooth. Don't rush here; sugar dissolves into cream for silkiness.
- Gently fold dry mix into yolk blend. Use rubber spatula; no vigorous stirring. Clumps kill lightness.
- In clean, dry bowl beat egg whites till foamy then gradually add remaining sugar (45 g) until stiff peaks form. Look for shiny, firm white peaks standing tall; over-beating dries whites, under-beating deflates.
- Fold a quarter of meringue into batter to loosen it. Then fold remaining whites gently but thoroughly, no lumps, no tough spots. A light hand keeps air trapped, making cake springy.
- Pour batter into pan. Smooth top gently with offset spatula.
- Bake 28–33 minutes. Start checking at 28 min. Toothpick inserted should come out clean or with a few moist crumbs. Top will be pale golden, edges just pulling from pan. Don’t overbake or cake turns dry.
- Cool on rack completely, 1 1/2 to 2 hours. Cooling important; warm cake drags moisture out from jam and glaze later.
- Remove from pan carefully by running knife around edges. Slide cake off parchment onto plate or cake board.
Rhubarb Jam
- Sprinkle gelatin over cold water; let bloom 5–6 minutes. Gelatin powder, not sheets, preferred for ease. Agar agar works but add once rhubarb is done and hot.
- In saucepan, combine rhubarb, sugar, lemon juice. Bring to gentle boil, then simmer medium heat 12–15 min until rhubarb breaks down and mixture thickens like syrup. Stir often to prevent sticking or burning. Aroma changes from sharp to mellow tart-sweet when ready.
- Remove from heat. Stir in gelatin till fully dissolved. Agar: sprinkle and whisk in, then simmer 2 more min.
- Pour jam into bowl; cover loosely, cool to room temperature. Refrigerate at least 1 hour till cold and set but spreadable, not rock solid.
Assembly
- Slice cake horizontally into two equal layers using serrated knife. Go slow; cake crumb fragile.
- Place bottom layer on serving plate. Spread chilled rhubarb jam evenly – don’t overload or cake will slide off.
- Set top layer gently over jam. Press lightly to attach but don’t squash airiness.
Elderflower Glaze
- Mix powdered sugar and elderflower syrup until glaze is smooth, opaque, and slightly runny. Add syrup or sugar incrementally. Should drip slowly off spoon but hold shape.
- Pour over cake, letting glaze flow elegantly down sides. Use spatula for coverage or just a ladle drizzle. Imperfections add charm.
- Decorate with edible flowers if desired; adds visual pop and subtle fragrance.
- Chill cake under dome in fridge. Keeps freshness 3 days max. Glaze softens slightly on cake surface; avoid warm rooms.
- == Tips & Troubleshooting ==
- Egg whites shouldn’t have any yolk traces—fat kills volume. Use copper or stainless bowls, no plastic residues.
- If cake cracks, reduce oven temperature slightly next time or rotate pan halfway through bake.
- Rhubarb jam too runny? Simmer longer or add little more gelatin next batch.
- No elderflower syrup? Substitute with honey or simple syrup infused with lemon zest, but flavor will shift.
- Glaze too thick? Thin with warmed water, little at a time. Too runny? Add more powdered sugar sparingly.
- Don’t skip chilling jam; warm jam makes layers slide or cake soggy quickly.
- Handling cake while still warm wrecks texture; patience pays off.
- Leftover jam is fantastic swirled into yogurt or spread on toast.
- Using frozen rhubarb? Thaw and drain excess liquid to avoid watery jam.
- Whisk cream and elderflower into batter adds moisture but be cautious – too much liquid deflates batter.
Cooking tips
Skipped linear step list for a more intuitive approach: cake, jam, assembly shine separately. Cake steps reordered slightly to emphasize cooling before unmolding and slicing. Egg whites whipped to stiff peaks; gradual sugar ensures glossy meringue crucial. Folding technique detailed – folded quarter first to loosen batter, then rest carefully – experience proves quick big folds ruin cake rise. Baking time flexible; temperature steady, watch toothpick, color, shrinkage instead. Jam instructions emphasize checking syrupy texture visually and on spatula; not just minutes. Gelatin bloom essential; skip and jam runs. Glaze mixed last; viscosity balance tricky, thin enough to pour not run off in rivers. Edible flowers optional, but bonus sensory touch. A few tweaks on times for margin, depending on oven quirks. Patience & eyes over clock.
Chef's notes
- 💡 Egg whites need clean bowl; no yolk fat slips in or volume tanks. Use copper or stainless; plastic holds grease and kills foam. Gradual sugar addition keeps whites glossy, stiff. Under or over beat ruins air structure; watch texture carefully, shiny stiff peaks stand tall not dry flakes.
- 💡 Gelatin bloom essential; cold water soak 5-6 minutes. Agar agar differs; add powdered only once rhubarb hot to dissolve properly, simmer longer. Too little gelatin and jam runs. Simmer rhubarb gently; watch bubbles shrink and aroma mellow. Jam thickens visually, not just by time.
- 💡 Bake with parchment only, no butter or flour; extra fat clogs crumb, makes crust tough. Springform pan edges grip better with parchment sole. Oven temp steady 180 C; watch toothpick from 28 mins. Pull edges slightly from pan starts when done. If overbaked edges dry, crumb tough, jam moisture lost.
- 💡 Fold batter slowly; quarter meringue first to loosen batter, rest gentle but thorough. Big folds flatten batter, dull rise. Rubber spatula key, no stirring. Batter texture silky, not lumpy. Adding cream or coconut milk moisture varies; too wet deflates meringue. Adjust liquid with caution, fold slow.
- 💡 Glaze viscosity tricky; mix powdered sugar with elderflower syrup bit at time. Too thick coats uneven, looks dull; too thin runs off cake sides fast. Should drip slowly, hold shape mostly. Edible flowers add aroma and contrast but optional. Chill cake to set glaze, avoids slide or melting.
Common questions
How to replace gelatin if vegan?
Use agar agar powder instead, 8 ml to 5 ml gelatin. Add to rhubarb only when hot after cooking. Simmer 2 more minutes for full dissolve. Gelatin bloom skipped. Texture shifts slightly firmer with agar but workable.
What if jam is too runny?
Simmer longer on medium heat. Watch syrup consistency on spoon for sticky, thick coat. Add extra gelatin little by little; bloom separately. Cool then test spreadability. Too watery comes from insufficient simmer or too much liquid used.
Can cream be replaced?
Yes, coconut milk works best substitute; 35% fat mimics heavy cream. Flavor shifts slightly tropical but body stays. Coconut milk doesn’t whip well so rely on meringue stiffness. Important to avoid excess liquid to keep airy crumb intact.
How to store leftover cake?
Refrigerate under dome or loosely cover. Keeps moist 2-3 days. Jam moisture pulls in slowly; glaze softens but holds. Freezing possible but texture changes; thaw at room temp wrapped, not fridge. Watch condensation on glaze when thawing.
