01 -
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until evenly mixed.
02 -
Using a hand or stand mixer, beat the softened butter and granulated sugar together until light and fluffy, approximately 2 minutes.
03 -
Add the egg, sour cream, and vanilla extract to the creamed mixture, beating until smooth and well combined.
04 -
Gradually add the dry ingredients to the wet ingredients, mixing until just combined to maintain tenderness. Avoid overmixing.
05 -
Divide the dough into two equal portions, shape each into a disc, wrap in plastic wrap, and refrigerate for at least 1 hour or overnight.
06 -
Preheat the oven to 350°F (177°C) and line baking sheets with parchment paper.
07 -
On a lightly floured surface, roll out the chilled dough to approximately 1/4 inch thickness. Cut into desired shapes using cookie cutters and transfer to prepared baking sheets.
08 -
Bake for 8 to 10 minutes, or until edges are lightly golden. Allow cookies to cool on the baking sheet for 2 minutes before transferring to a wire rack to cool completely.
09 -
Beat the softened butter in a medium bowl until creamy. Gradually add powdered sugar, one cup at a time, mixing until smooth. Stir in vanilla extract and 1 to 2 tablespoons of milk, adjusting for a spreadable consistency. Optionally, divide and tint the frosting with food coloring.
10 -
Spread or pipe the frosting onto completely cooled cookies. Add sprinkles or decorations if desired. Allow frosting to set before storing.