Step 1: Preheat and Prepare
Preheat the oven to 350°F (175°C). Grease and line a loaf pan with parchment paper.
Step 2: Mix Dry Ingredients
In a bowl, combine flour, cocoa powder, baking soda, and salt. Set aside.
Step 3: Prepare Wet Ingredients
In another bowl, beat eggs, sugar, melted butter, vanilla, and Greek yogurt until smooth. Stir in mashed bananas.
Step 4: Combine Wet and Dry
Gradually add the dry ingredients to the wet mixture and stir until just incorporated.
Step 5: Add Chocolate
Fold in the dark chocolate chips.
Step 6: Bake
Pour the batter into the prepared loaf pan. Bake for 50 minutes or until a toothpick comes out clean. Let cool.
Step 7: Make Espresso Glaze
In a small saucepan, combine espresso, cocoa powder, and butter. Whisk until smooth, then stir in powdered sugar.
Step 8: Drizzle and Serve
Drizzle the espresso glaze over the cooled banana bread. Slice and serve.