Brown Butter Banana & Chocolate Marble Cake

This is a back to basics kind of week.  Nothing very fancy or complicated, just simple ingredients you can find just about anywhere.  But since it’s also essential to have some fun in the kitchen, I mix things up just a little bit.

I start this pastry with a basic banana bread idea, which we all know and love.  Some banana breads are made with butter and some are made with oil.  Some have nuts and/or chocolate chips.  Some are hydrated with buttermilk and some just use a lot of bananas for more moisture.  

In this recipe I brown the butter to a nice nutty amber for additional flavor.  I add a pinch of spice and I use sour cream for moisture.  I’ve found that sour cream works best to really tenderize banana cake.  I use a mix of granulated & brown sugars for flavor and moisture.  I add bananas that are very ripe to make sure the right sugar levels are there.  And just to make matters more alluring, I portion a bit of the batter and flavor it with a cocoa & coffee mixture.  Then it's crowned with chopped nuts and into the oven it goes.

The resulting cake is tender with a soft crumb, not too heavy and perfect for an afternoon snack or morning brunch table when you feel like it's time for a little treat. 

Bench notes:

- Some tips for successful browned butter:

1) Use a stainless steel pan so you can best gauge the color of the butter as it starts to brown.  Have a small heatproof bowl near the stove so you can immediately pour off the butter when it's done.  I use a clear Pyrex custard cup so I can see the color.

2) Cut the butter into small uniform pieces so it melts consistently without spot scorching.

3) Use medium low heat and watch it carefully.  As the butter starts to melt and heat up, you'll notice small bubbles on the surface that get larger. You'll notice the milk solids starting to brown on the bottom of the pan very quickly.  Lift the pan and swirl for more control if it’s browning too fast or nearly done.  Keep your eye on it and keep swirling.  It will be done very quickly after you notice the first brown bits on the bottom of the pan.  Once you begin to detect a nutty aroma, it's about done.  Stop when you think it's almost there.  It will continue to darken off the heat.  Pour immediately into a heatproof bowl to stop the cooking.   Set aside to cool.

4) If you've gone too far, it will look very dark and taste bitter, so you'll have to start over again.  You’re looking for medium amber brown.

5) When adding the browned butter to the rest of the ingredients, include all the brown bits that have settled to the bottom of the bowl.

- I mashed the bananas fairly coarsely.  It's definitely not a puree.

- I tried this cake with melted chocolate rather than the cocoa mix and I prefer the flavor of the cocoa.

Brown Butter Banana Chocolate Marble Cake

Makes 1 loaf

4 oz (8 tablespoons) unsalted butter

1 1/2 cups (7 1/2 oz) flour

1 teaspoon baking powder

3/4 teaspoon baking soda

1/2 teaspoon salt

1 teaspoon cinnamon

pinch nutmeg

1/4 cup (3/4 oz) cocoa powder

1/4 cup (2 oz) hot coffee

3/4 cup (5 1/4 oz) sugar

1/4 cup (1 3/4 oz) brown sugar, packed

2 eggs @ room temperature

1 1/2 teaspoons vanilla

1 cup (6 3/4 oz; about 2 medium) ripe banana, mashed

1/3 cup (75 grams) sour cream

1/3 cup (about 1 oz) walnuts, coarsely chopped

Preheat oven to 350 degrees F.   Grease an 8 1/2" x 4 1/2” loaf pan and line with a piece of parchment paper large enough to form an overhang along both sides of the length of the pan.

Brown the butter until it’s medium amber.  Immediately pour into a heatproof bowl and allow to cool.

Sift together the flour, baking powder, baking soda, salt, cinnamon and nutmeg.  Set aside.

Combine the cocoa powder with hot coffee until smooth.  Set aside.

In a bowl large enough to hold all the batter ingredients, whisk together the cooled browned butter and both sugars.  Beat in the eggs and vanilla extract and mix thoroughly.  

Add half of the flour mixture and stir to combine.  Blend in the sour cream and bananas and mix thoroughly.  Add the remaining flour mixture and mix just until there are no more flour streaks.  Remove 3/4 cup of the batter and combine with the cocoa/coffee mixture.

Pour half the banana batter into the prepared pan.  Dollop with half the chocolate batter and run a knife through in figure 8s to marble.  Repeat once again.  Press chopped nuts onto the top.  


Bake for 45 - 50 minutes or until a toothpick inserted into the center of the cake comes out clean. Place cake on a wire rack to cool for 10 minutes.  Run a thin knife around the edges to loosen.  Using the parchment overhang to assist, lift the cake out and cool completely.