Brown Butter Banana Brownies

Name: Brown Butter Banana Brownies
Prep time: 15 min
Cook time: 22 min
Total time: 37 min
Yield: 24 servings
Ingredients: 2 cups all-purpose flour; 1 teaspoon baking powder; 1 teaspoon baking soda; 1 teaspoon ground cinnamon; 1/2 teaspoon salt; 1/2 cup unsalted butter softened; 1/2 cup brown sugar packed; 1/2 cup granulated sugar; 2 large eggs; 1 cup very ripe mashed banana (about 2-3 medium bananas); 1/2 cup plain yogurt (substitute for buttermilk); 2 teaspoons vanilla extract; 1 cup chopped walnuts; 1/2 cup unsalted butter (for frosting); 2 cups powdered sugar; 1/3 cup half and half cream; 1 teaspoon vanilla extract

By Emma

Certified Culinary Professional

Published on 09 October 2025 • Recipe tested & approved

A cross between banana bread and brownies, moist and dense with browned butter frosting. Uses mashed ripe bananas and browned butter for nutty depth. Brown sugar and granulated sugar for textured sweetness. Walnuts add crunch. Uses baking powder and baking soda for rise, cinnamon for warmth. Creamy browned butter frosting with half and half for richness. Slightly less sugar and a swap from buttermilk to plain yogurt for tang. Bake until edges golden and tester picks a few moist crumbs. Nutty aroma signals frosting readiness. Quick bake and immediate frosting spread keeps top tender.

Prep: 15 min

Cook: 22 min

Total: 37 min

Servings: 24 servings

#baking #brownies #banana #brown butter #nuts #dessert

Before You Start

Brownies with mashed bananas instead of straight cocoa-heavy stuff. Soft, chunkier than your usual dense chocolate bars but with that richness. Tried skipping brown sugar once— lost depth, so no. But swapping buttermilk for yogurt worked; tang stayed but yogurt made batter slightly thicker. That browned butter frosting? Took me a while to nail the timing; too long on heat and bitterness kicks in. Learning to smell the bubble-foam transition saved my afternoon. These bake fast; edges turn golden first, center still moist. Crumbs on tester is best, not dry or liquid goo. Walnuts are a must; earlier runs without had no personality. Don’t let batter linger or it dries out. Spread frosting while warm so it melts in and glazes top. Keeps longer in fridge if wrapped.

Ingredients

2 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon ground cinnamon
1/2 teaspoon salt
1/2 cup unsalted butter softened
1/2 cup brown sugar packed
1/2 cup granulated sugar
2 large eggs
1 cup very ripe mashed banana (about 2-3 medium bananas)
1/2 cup plain yogurt (substitute for buttermilk)
2 teaspoons vanilla extract
1 cup chopped walnuts
1/2 cup unsalted butter (for frosting)
2 cups powdered sugar
1/3 cup half and half cream
1 teaspoon vanilla extract

About the ingredients

Bananas must be very ripe; brown spots or black skin. Riper means more flavor and moisture. If you’re out of plain yogurt, sour cream substitutes nicely for tang and texture. Butter needs to be just softened not melted for the batter or sugars won’t aerate properly. Brown sugar adds moisture and chew; swapping all granulated makes texture too dry. For walnuts, toasted ones punch up nuttiness but raw works in pinch. Powdered sugar needs sifting to avoid lumps in frosting. Half and half cream can be replaced by whole milk but frosting loses silkiness and sets firmer. Vanilla extract essential; don’t skip or lower amount or it tastes flat. Flour measured spooned and leveled—too much dries batter. Baking soda and powder combo balances rise and browning; don’t swap all with one.

Method

Heat oven to 350F. A 9x13 pan sprayed or lined with parchment, or buttered thoroughly.
Whisk flour, baking powder, baking soda, cinnamon, salt in medium bowl. Set aside.
In big bowl, beat softly softened butter and both sugars until lighter, fluffy but don’t overdo or it can get greasy.
Add eggs one at a time, mixing well after each. Stir in mashed banana, yogurt, vanilla. The batter will smell like ripe fruit and a bit tangy now.
Gradually sift in flour mixture, folding or mixing until just combined. Overmixing kills tenderness here.
Fold in walnuts gently. Save a few to sprinkle on top if you like extra crunch.
Pour batter into pan, spread evenly. Bake around 22 minutes. Look for golden edges pulling slightly away from sides. Tester won't come out dry but with moist crumbs.
While baking, melt frosting butter in skillet over medium. Watch carefully— it bubbles then foams, swirls turn from pale yellow to deep amber. Nutty smell is key. Remove immediately; don’t burn.
Off heat, whisk in powdered sugar, half and half, and vanilla till smooth, spoonable frosting forms.
Once brownies out and still warm, spread frosting thinly with spatula. If it cools too much first, frosting thickens and doesn't spread well.
Let cool fully for cutting. Store airtight to retain moisture.

Cooking tips

Whisk dry ingredients separately to avoid pockets of baking soda or salt. Creaming sugars and butter traps air for lightness; if butter too cold, beat longer or soften more first. Add eggs slow so batter emulsifies properly. Mixing flour last and gently prevents gluten overdevelopment and tough brownies. Walnuts stir in last so they don’t grind or break down. Visual checks critical: edges turn gold first, center jiggles slightly but holds. Testing center with toothpick; wet batter means not done, dry means over. Brown butter for frosting requires constant attention—foam rises, shifts to brown spots, then releases a nutty smell just before burning. Off heat mixing smooths frosting. Apply frosting ASAP while brownie warmth helps spread and glue it. Cooling completely firms texture and stops frosting sliding off. Slice with serrated knife or warm knife to clean edges. Store covered at room temp 2-3 days, fridge longer but bring back to room temp before cutting.

Chef's notes

💡 Whisk dry mix separately. Baking soda got pockets risk. Cream butter soft, not melted. Beat sugars till fluffy. If butter cold, batter dense, greasy. Eggs—add slow. Emulsify or batters split. Flour last, fold gently. Gluten toughens if stirred fast or rough. Walnuts go in near end; crushing ruins texture, signals burnt nut bitterness early. Tester toothpick look—dry crumb or moist bits. Don’t overbake or edges dry. Golden edges pulling away signal finish.
💡 Brown butter carry aroma clues—listen for bubbles, foam, then slow-dark brown spots appear. Nutty scent switches from sweet cream to deep roast. Pull off heat fast or bitterness shadows. Whisk in powdered sugar, vanilla, half and half quick, frosting thickens fast. If cool, thick clumps form. Spread right away while warm. Use spatula strokes, thin or thick layer, watch melting into surface. Warm brownie helps gloss, adhesion. Cooling hardens frosting, or too cold won’t melt in.
💡 Bananas must be ripe—black or brown peel. Under-ripe means bland, dry texture. Riper adds sweetness, moisture. If yogurt missing, sour cream stand-in. Slight flavor shift, same tangy lift. Sugar balance matters. Brown sugar adds chew. Swapping all granulated makes final crumb dry and flat. For nuts, toasted obsessed folks get nuttier hits. Raw walnuts safe but misses deeper flavor. Powdered sugar sifting stops lumps, clumps. Watch frosting texture—too thick means add cream little by little till spoonable.
💡 Texture clues rule. Batter scented of banana, cinnamon, vanilla, faint tang. Thickness signals. Overmixing kills crumb—no bounce back, flat. Fold flour; stubborn lumps ok than too stirred. Tester toothpick critical. Few moist crumbs fine, drier means overdone. Baking time vary by oven. Pan prepped every bake; parchment or butter both work. Butter softened right—too warm butter no fluff; cold butter batter stiff. Timing in mixing and baking varies by local climate/humidity too.
💡 Frosting tricky. Brown butter timing is everything. Too early or too late bitter. Watch color constantly. Brown spots pop up, bubble stages fade. Smell guides. Off heat whisk quickly. Frosting thick but spoonable only warm. If cooling starts frosting hardens or clumps. Apply ASAP. After frosting, chill or room temp ok. Wrapped keeps moist. Knife serrated or warmed. Slicing warm or room temp smooth. If fridge chilled, warm up slices before serving so frosting isn’t rock hard or crumbly.

Common questions

Can I use sour cream instead of yogurt?

Yes, sour cream swaps well for tang, texture close, maybe thicker batter Slightly different flavor. Use same volume. Might need slight stirring adjustments.

What if butter too cold or melted for batter?

Butter too cold means sugars won’t aerate right, dense mix. Melted butter kills fluff, greasier texture. Softened means room temp, still solid but pliable. Beat longer if unsure.

How judge frosting readiness?

Watch butter color bubble foam. Nutty aroma key. Brown spots form before burning. Pull off heat fast. Whisk immediately. Too dark equals bitter. Smell beats timer every time.

How store these brownies?

Room temp airtight 2-3 days, keeps moist. Fridge extends life, but hardens frosting. Bring back to room temp slices better, softer texture. Can freeze; wrap tight, thaw well before cutting.