In a mixing bowl, beat butter, sugar and egg until creamy.
Add cream cheese, buttermilk (yogurt) and vanilla and beat until smooth.
Beat in flour, baking powder, salt and baking soda.
Cover dough in plastic wrap and chill for at least one hour. optional: For drop cookies, skip chilling step and bake immediatelyFor sliced cookies, roll into a 2 inch thick cylinder then wrap and chill.
Preheat oven to 350°F.
Drop: After mixing dough, drop by tablespoonful on a baking sheet 2 inches apart.Cut out: roll dough out on a floured board to ⅛ inch thick and cut with cookie cutters. Place 1 inch apart on baking sheet.Roll and press: Roll into 1 inch balls, place on baking sheet 2 inches apart then press with cookie press or bottom of a glass.Sliced: Slice ⅛ thick slices from the cylinder of dough and place 1 inch apart on a baking sheet.
If desired sprinkle cookies with sprinkles or cinnamon sugar.
Bake for 12-15 minutes until just set in the middle. Remove from cooking sheet and allow to cool on a cooling rack.