Prep the Pan: Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking pan with butter or cooking spray and line with parchment paper, leaving some overhang.

Melt Chocolate & Butter: In a medium saucepan, melt ½ cup of unsalted butter and 1 cup of chopped semisweet chocolate over low heat, stirring until smooth and glossy for about 5-7 minutes. Remove from heat and let cool slightly.

Combine Ingredients: Whisk in 1 cup of granulated sugar, then add 2 large eggs one at a time, followed by 1 teaspoon of vanilla extract and 2 tablespoons of Vietnamese coffee powder. Mix until smooth.

Mix Dry Ingredients: In a separate bowl, whisk together ½ cup of all-purpose flour and ¼ teaspoon of salt. Gradually fold this mixture into the wet ingredients until just combined.

Add Condensed Milk: Pour half of the brownie batter into the prepared pan, swirl ½ cup of sweetened condensed milk over the batter, then top with the remaining batter and swirl again.

Bake: Bake for 35-40 minutes, until a toothpick inserted in the center comes out with a few moist crumbs. Allow to cool.

Cool: Allow brownies to cool in the pan on a wire rack for at least 20 minutes before lifting out and slicing.