Preheat oven to 350°F (175°C). Grease a 9x5 inch loaf pan and line with parchment paper

In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt

In a large bowl, whisk together sugars, oil, eggs, and vanilla until well combined

Gradually add dry ingredients to wet ingredients, mixing until just combined

Stir in hot coffee or water until batter is smooth (it will be thin)

In a small saucepan, combine chocolate chips, cream, cocoa powder, sugar, butter, and salt

Heat over low heat, stirring constantly, until smooth and glossy (about 3-5 minutes)

Remove from heat and let cool slightly

Pour half of the brownie batter into prepared pan

Drizzle half of the hot fudge over the batter and swirl with a knife

Add remaining batter, then top with remaining hot fudge, swirling again

Bake for 55-65 minutes until a toothpick inserted comes out with moist crumbs

Cool in pan for 15 minutes, then transfer to wire rack to cool completely