Step 1: Preheat the oven to 220 degree Celsius.
Whisk the butter, yogurt, lemon juice, food colour till frothy, for about ten minutes.
Sift the flour, cocoa powder, baking powder and baking soda twice.
Step 2: Divide this flour mixture to four equal parts.
Add each batch into the butter mixture by whisking continuously.
Whisk for ten minutes.
Step 3: Scoop a tablespoonful of batter into the nonstick baking tray and bake in the preheated oven for thirty minutes.
Step 4: Bake until the cookies spring back when lightly pressed.
Let it cool for ten minutes.
Step 5: Filling :
Beat the butter and icing sugar well.
Add the vanilla essence and mix well.
Sandwich a heaping tablespoonful of filling between two cookies , repeat with the remaining cookies.
Step 6: Refrigerate for 30 minutes before serving.
Red velvet whooping pie is ready to serve.