• Preheat the oven to 350˚F. Grease and flour a 9x13-inch pan or two 9-inch round pans; set aside.
• Sift flour, baking powder, and salt together; set aside.
• In a large mixing bowl, beat butter and sugar until creamy and fluffy. Add the eggs, one at a time, beating well after each addition. Add the vanilla extract and mix well
• Add the dry ingredients alternating with the milk to the butter mixture and stir well.
• Pour the batter into a prepared pan and bake for 30-40 minutes. If using two 9-inch round pans, bake for 25-30 minutes. Let the cake cool completely. If using 9x13-in pan, you can cool the cake in a pan, If using the two round pan, after cooling in a pan for 10 minutes, turn out the cake to a cooling rack and cool completely.

For the chocolate frosting

• Put unsweetened chocolate pieces in a small microwave-safe mixing bowl and microwave for 90 seconds, stirring halfway through. Stir the chocolate well until you melt them completely. Set aside to cool.
• Cream butter and powdered sugar until fluffy. Add the cooled chocolate and vanilla extract and continue to beat. Adjust the amount of powdered sugar until your get the desired consistency.
• Spread the frosting over the cake and serve. The leftover cake can last in the room temperature for 3 days or chill in the fridge up to a week.