Preheat oven to 325 degrees F. Spray 9x13” baking dish with cooking spray and set aside.
In a small bowl, combine flour, baking powder, and salt. Set aside.
In small saucepan, melt butter over medium heat, stirring frequently.
Once melted, add chocolate and stir continuously until melted.
In bowl with electric mixer, combine butter/chocolate mixture with sugar.
Mix with electric mixer until well combined.
Add eggs, one at a time, beating until each one is combined.
Add vanilla and Kahlúa, and mix well.
add flour mixture to wet ingredients and stir until combined.
Fold in chocolate chips.
Transfer batter to prepared baking dish and bake in preheated oven for 35-40 minutes, until toothpick comes out clean.