Peanut Butter brownie dream cupcake

In a medium sized microwave safe bowl, combine sugar, butter, and water. Microwave on high, about 45 seconds, or until butter is melted. Stir ingredients to combine, then add in 3/4 cup semi-sweet chocolate chips and stir until melted. Add in egg and vanilla extract, mix well. Add flour and baking soda and mix until combined. Allow the batter to cool to room temperature, about 5 minutes. Then stir in 3/4 cup milk chocolate chips and remaining 1/4 cup semi-sweet chocolate chips. Spoon batter evenly into lined muffin tin. Bake 13-15 minutes or until top sets and a toothpick inserted comes out slightly wet. Remove brownies and wait for centers to fall, which happens upon cooling. If center doesn't fall, slightly tap with the back of a teaspoon to make a hole for peanut butter. Place peanut butter in a small microwave-safe bowl and microwave on high 15-30 seconds until soft. While brownies are still warm, spoon peanut butter into center of brownie and top with remaining 1/3 cup milk chocolate chips. Cool completely in pan. Serve at room temperature, or warm in microwave 10-15 seconds.