Melt semi-sweet and german sweet chocolate and set aside to cool until just warm & not hot.
Chop candy into small pieces, then set aside.
In a stand mixer fitted with the paddle attachment or a large bowl, beat cream cheese until smooth.
Add powdered sugar and cocoa powder. Beat until smooth.
Add in eggs one at a time. Mixing on low speed after each addition. Do not over beat.
Add in melted chocolate and mix on low speed until combined.
Use a wooden spoon to fold in chopped candy (reserving at least 1 cup of chopped candy for topping).
Pour the chocolate filling over the crust and smooth out the top.
Add water bath to oven: fill a separate pan with 2 inches of warm water and place on the rack below where the cheesecake will be baking (I typically use a roasting pan).
Bake the cheesecake until there is a 2-inch jiggle at the center (45 mins-1 hour), then turn off the oven but leave the cheesecake inside.
Leave the cheesecake in the oven for another 45 minutes to 1 hour. Then remove and cool until it is at room temperature.
Run a thin knife around the sides of the pan then remove the spring-form. Cool in the fridge for at least 4 hours (better to wait overnight).