Whenever my mother had leftover sour cream that was still safe to eat but had been hanging around the fridge for too long for it to taste fresh, she would use it to bake something. Like her marble cake. 

That cake was a simple wonder. Tender, vaguely sweet, with just enough melted chocolate swirling through the vanilla crumb. Rarely frosted, we ate it like coffee cake, just as is.

I've made that cake many times, and for the same reasons. Leftover sour cream (I also use leftover plain Greek yogurt when I have some). I've made it the original way and with coconut oil in place of shortening. 

Recently I had sour cream and yogurt leftover, the not exactly new kind.

I also had bananas left over. I always have bananas left over. I usually make banana bread with the leftover bananas.

So I took a cue from my mother and decided to bake marble cake. Using bananas.

So good.

Banana Marble Cake

• 4 ounces semisweet chocolate
• 2-1/2 cups all-purpose flour
• 1 teaspoon salt
• 2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1 cup sugar
• 3 large eggs
• 1 teaspoon vanilla extract
• 1/2 cup vegetable oil
• 4 very ripe medium bananas, mashed
• 1 cup dairy sour cream or plain Greek yogurt 

Preheat the oven to 350 degrees. Grease and flour a (10-inch) 8-cup bundt pan. Melt the chocolate and set it aside. Mix the flour, salt, baking powder and baking soda together in a bowl and set aside. In the bowl of an electric mixer set at medium speed, beat the sugar and eggs for 2-3 minutes or until well blended. Add the vanilla extract and vegetable oil and beat for 1-2 minutes or until thoroughly blended. Add the bananas and sour cream and beat them in. Add the flour mixture and beat for 1-2 minutes or until the batter is well blended. Pour half the batter into the prepared pan. Pour in half the melted chocolate and swirl it into the batter using a knife or wooden spoon. Repeat with the remaining batter and melted chocolate. Bake for 50-60 minutes or until a cake tester inserted into the center comes out clean. Remove from the oven and let cool in the pan for 10 minutes. Remove to a cake rack to cool completely.

Makes one bread, serving 12-16