Line a 9 inch / 24 cm spring form pan with a circle of baking paper. Preheat oven to 340°F/ 170°C.
In a food processor crush the biscuits into crumbs. Combine with melted butter and mix until homogeneous. Press the prepared crust onto the bottom of the spring form pan. Leave the pan in the freezer while preparing the filling.
In a large mixing bowl whisk together cream cheese and sugar until fluffy. Add sour cream, yogurt, cocoa, vanilla and eggs (one at a time) and whisk until combined. Do not overmix! Finally add the food colouring. Stir until absorbed.
Pour the filling in the pan over crust. Bake between 1 and 1,5 hours or until the edges are firmer but the center is still soft.
Remove the cheesecake from the oven and allow to cool for 10 minutes before carefully running a knife around the edge of the pan. Let it cool completely before frosting.
Frosting:
Beat cream cheese and butter until fluffy. Add powdered sugar and vanilla and beat until homogeneous. Frost the top of the cheesecake and transfer it to the fridge. Refrigerate at least 6-8 hours or overnight before serving.