Using the mixer, start by softening the cream cheese by mixing it for a minute.
Mix in the sugar until it dissolves in the cream cheese, then add in the eggs, followed by the sour cream and whipping cream. Make sure they are well incorporated.
Add the chocolate chips and butter to a bowl and place the bowl in the microwave till the chocolate melts and is mixed with the butter.
Add to the chocolate the vanilla and sugar. Add in the eggs one by one with constant mixing.
After mixing in the eggs, add the flour, cocoa powder, and salt. Mix well.
Line a muffin tin with muffin liners. Pour in each muffin liner the brownie batter, make sure 2/3 of the muffin liner is filled with the batter.
Fill with the cheesecake batter the remaining 1/3 of the muffin liner. Swirl both the brownie with the cheesecake for the best look.
Bake for 15 minutes in a preheated oven at 350 degrees.
Let them cool on a cooling rack. You can serve them after cooling or chilled.