• Preheat oven to 350°F. Gather the ingredients for this recipe so you have everything close at hand on the counter or table.
• Line a muffin tin with jumbo-sized muffin liners to make 12 extra large muffins.
• (If you don’t have jumbo-sized muffin liners, you may simply make 15-16 regular muffins or use a jumbo muffin tin.)
• Place peeled bananas in a large bowl and mash with a blending fork. For this recipe, I used 2 large ripe bananas to make 1-1/2 cups of mashed bananas.
  1 1/2 cups ripe bananas

Prepare the Batter

• Place all-purpose flour in a large batter bowl. Add in granulated sugar, baking cocoa, baking powder, baking soda, and salt. Mix together with a whisk until blended.
  2 cups all-purpose flour, 1 cup granulated sugar, 1/2 cup baking cocoa, 1 teaspoon baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon salt
• Next, add the unfed sourdough to the mashed bananas. Mix in the buttermilk, vegetable oil, large egg, and vanilla extract until combined. Add this to the flour mixture, and carefully fold in until the flour is fully incorporated.
  1 cup sourdough starter discard, 1/2 cup buttermilk, 1/4 cup vegetable oil, 1 large egg, 1 teaspoon vanilla extract
• Lightly mix in 1 cup of the mini semi-sweet chocolate chips.
  1 1/4 cups mini semi-sweet chocolate chips

Fill Muffin Cups and Bake

• Using a large spoon or cookie scoop, drop batter into prepared muffin cups, filling 3/4 full. (I do not own an oversized muffin tin, but the jumbo-sized muffin liners allowed me to fill the muffin cups extra full so that I was able to use all of my batter in one baking pan.)
• Sprinkle remaining 4 tablespoons of mini semi-sweet chocolate chips over the tops of the muffins.
• Bake in preheated oven for 25-30 minutes, until the edges are lightly browned and the tops spring back when touched.
• Cool for 5-7 minutes and then transfer muffins to a wire cooling rack. This recipe will make 12 jumbo-sized muffins.