In the bowl of a stand mixer, combine butter and sugar. Beat with the paddle until creamy. Add the egg and beat until blended, then beat in the cake batter extract.
Mix together the flour, baking powder, baking soda, cream of tartar and salt. Add to the bowl and stir until almost fully blended, then stir in the whipping cream.
Stir in the sprinkles. Using a small (1 inch) size cookie scoop, scoop out balls of dough and put them on a dinner plate or two lined with plastic. Cover and chill for 3 hours or until ready to bake.
Preheat oven to 350 degrees F. Have ready an ungreased or parchment lined baking sheet.
Roll dough balls in sugar and arrange on baking sheet. Put a few extra sprinkles on top if desired.
Bake at 350 for about 12 minutes. Let cool on baking sheet for 5 minutes, then transfer to a wire rack and let cool completely.