Preheat your oven to 350°F (175°C) and prepare your loaf pan by greasing it or lining with parchment paper.

In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt until no lumps remain.

In a larger bowl, whisk the eggs and sugar until smooth, then mix in the melted butter and vanilla.

Stir in the hot fudge sauce until the mixture is smooth.

Fold the dry ingredients into the wet mixture until just combined.

Pour the batter into the prepared loaf pan and spread evenly.

Bake for 35-45 minutes or until a toothpick comes out clean or with a few moist crumbs.

Let the bread cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

Slice and serve, optionally drizzling with extra hot fudge sauce.