Preheat your oven to 350°F. Grease a 9x5-inch loaf pan and set aside.
In a large mixing bowl, whisk together the flour, granulated sugar, brown sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
In another bowl, mix the melted butter, eggs, and vanilla extract until smooth.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Fold in the hot fudge sauce and chocolate chips until evenly distributed.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 45-50 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Allow the brownie bread to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
Slice and serve warm or at room temperature.