Combine feta, hot sauce, and egg in a bowl and whisk until smooth.

Mix flour and sour cream to form a soft dough. Adjust consistency with more flour or sour cream as needed.

Turn out dough onto floured surface and roll to 1/4 inch thickness.

Cut into 3-inch rounds using cookie cutter, rerolling scraps as needed.

Place filling in center of each round, fold in half, and crimp edges with fork to seal.

Heat vegetable oil in skillet to 350°F.

Cook pierogies in hot oil for about 2 minutes per side until golden and floating.

Remove and drain on paper towels.

Serve warm with toppings of your choice.