Preheat the oven to 350°F (175°C). Grease and line a 9x5-inch loaf pan with parchment paper, letting the sides overhang for easy removal.

In a medium bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and instant coffee granules (if using) until evenly combined.

In a separate large bowl, cream the unsalted butter and brown sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Mash the very ripe bananas until smooth and fold them into the butter-sugar-egg mixture.

Alternately add the dry ingredients and the milk to the wet mixture, beginning and ending with the dry ingredients. Mix gently until just combined — a tender crumb is the goal.

Fold in the chocolate chips with a spatula, being careful not to overmix.

Pour the batter into the prepared loaf pan, smooth the top, and bake for 50–60 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs (not wet batter).

Let the loaf cool in the pan for 10–15 minutes, then lift it out using the parchment overhang and let it cool completely on a wire rack before frosting.

Heat the heavy cream in a small saucepan (or in a microwave-safe bowl) until it just begins to simmer — do not boil.

Place the dark chocolate in a heatproof bowl. Pour the hot cream over the chocolate and let it sit for 1–2 minutes, then whisk until smooth and glossy to create a truffle ganache.

Allow the ganache to cool and thicken slightly — you want it pourable but not too thin.

Once the loaf has cooled, pour or spread the ganache over the top, letting it drip slightly down the sides for an elegant finish.

Sprinkle a few extra chocolate chips or a light pinch of flaky salt if desired.