1. Preheat oven to 350 degrees.
2. In a large bowl mix together flour, baking powder, baking soda, salt and sugar to prepare the cake mixture. Add in melted butter and stir to combine. Add in one of the eggs and stir to combine well. Press mixture into an 8x8 sized baking pan and set aside.
3. Place the chopped peanut butter cups into the pan on top of the cake mixture. Sprinkle with 1/2 cup chocolate chips and 1/2 cups peanut butter chips.
4. In a separate bowl mix together softened cream cheese, egg, vanilla and powdered sugar. Stir until well combined then pour mixture over the top of your cake mixture and chocolates. Spread gently with a spatula to cover. Sprinkle top of cream cheese layer with remaining chocolate and peanut butter chips.
5. Bake for approximately 30-35 minutes or until golden brown. Remove from oven and let cool. Store in fridge (though take out of fridge about 10 minute prior to eating). Enjoy!