Preheat the oven to 350°F (180°C) and grease a 9-inch springform pan.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and cocoa powder.
Add vegetable oil, buttermilk, eggs, blackcurrant food coloring, vanilla extract, and white vinegar. Mix until well combined.
Pour the batter into the prepared pan and bake for 25-30 minutes or until a toothpick inserted in the center comes out clean. Let it cool.
In a mixing bowl, beat cream cheese until smooth. Add powdered sugar, vanilla extract, and pureed blackcurrants. Mix until well combined.
In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture.
Spread the blackcurrant cheesecake filling over the cooled cake base. Chill in the refrigerator for at least 4 hours or overnight.
Before serving, decorate with fresh blackcurrants and whipped cream if desired.
