Step 1: Preheat the oven to 350°F (175°C).
Step 2: Cream together the softened butter and brown sugar until light and fluffy.
Step 3: Add the eggs and vanilla extract, beating until well combined.
Step 4: In a separate bowl, whisk together flour, baking powder, cocoa powder, and salt.
Step 5: Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Step 6: Stir in the vinegar and red food coloring until evenly distributed.
Step 7: Place the pie crust in the pie dish and pour the batter into it.
Step 8: Bake for 25-30 minutes or until a toothpick comes out clean.
Step 9: Beat the cream cheese with granulated sugar and vanilla until smooth.
Step 10: Whip the heavy cream until stiff peaks form.
Step 11: Fold the whipped cream into the cream cheese mixture.
Step 12: Spread the cream cheese filling over the cooled pie.
Step 13: Chill the pie for at least 2 hours to set.
Step 14: Slice and serve cold, optionally with chocolate sauce.