Brown Butter Banana Cupcakes with Fudge Centers

Steps

1. Preheat the oven to 350°F (175°C) and line a 12-cup muffin pan with paper liners.
2. Brown the butter: melt the butter in a small saucepan over medium heat, swirling, until it smells nutty and the bits turn golden brown, 4 to 5 minutes. Pour it into a large bowl and cool 10 minutes.
3. Make the cocoa filling while the butter cools: whisk the unsweetened cocoa powder and powdered sugar in a small bowl, then whisk in the warm whole milk until smooth. Stir in the chocolate chips until melted and glossy, warming in short bursts if needed. Set the cocoa filling aside to thicken.
4. In a medium bowl, whisk the flour, baking soda, baking powder, salt and half of the cinnamon.
5. Into the browned butter, whisk the mashed banana, brown sugar, egg, Greek yogurt and vanilla until smooth.
6. Fold the flour mixture into the banana mixture just until no dry streaks remain.
7. Spoon a little more than half of the batter evenly into the liners. Add a heaped teaspoon of the cocoa filling to the center of each, using half of the cocoa filling in all. Cover with the remaining batter.
8. In a small cup, stir the granulated sugar with the remaining half of the cinnamon and sprinkle this cinnamon sugar over the tops.
9. Bake 18 to 22 minutes, until a toothpick inserted at the edge of the cake (not the fudge center) comes out clean.
10. Cool in the pan 10 minutes, then move to a rack to cool completely, about 45 minutes.
11. Warm the remaining half of the cocoa filling slightly and drizzle it over the cooled cupcakes.