Preheat over to 350 degrees and line an 8×8 inch cake pan with parchment paper so that the edges overlap over the sides.
In a large bowl combine butter, sugar, cocoa powder, and salt. Mix until well combined. Stir in the vanilla and then the eggs, one at a time, mixing very well after each addition. Add the flour and mix until combined. Spread into prepared pan and bake for 15 minutes.
Brownies should be slightly set, but not fully baked. Set aside to cool.
Filling:
(8-ounce) packages cream cheese, softened
/3 cup light brown sugar
large eggs, room temperature
/2 cup smooth peanut butter
teaspoon vanilla extract
/8 teaspoon salt
Using a hand or stand mixer, beat cream cheese and sugar on medium-high speed until well combined and smooth. Beat in the eggs, one at a time, until combined. Add in the peanut butter, vanilla, and salt and beat until just combined. Pour over the cooled brownie crust.
Bake at 350 degrees for 30 minutes. Filling should be set around the edges and slightly jiggly in the center. Allow to cool at room temperature on a cooling rack for 1 hour and then refrigerate to chill through.
Topping:
Heat whipping cream until it comes to a low boil. Place chocolate and peanut butter chips into two separate bowls and pour equal parts of the whipping cream into each bowl. Allow to set for 1 minute to melt chips.
Mix each bowl until each is well combined, allow to set for 5 minutes to thicken. Drizzle over cooled cheesecake