In a medium-sized bowl, whisk together 5 cups of the flour, baking soda, and baking powder. Reserve the remaining 1 cup of flour for adjusting dough consistency later, if needed.

In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and granulated sugar on medium speed until the mixture is light and fluffy, approximately 3 minutes. Scrape down the sides of the bowl as needed.

Add the eggs one at a time, mixing well after each addition. Blend in the vanilla extract and sour cream until fully combined. The mixture will appear thick and creamy.

Gradually add the flour mixture to the wet ingredients, mixing on low speed until just combined. If the dough remains too sticky for rolling, incorporate additional flour, ¼ cup at a time, until it reaches a pliable consistency. Do not exceed 1 cup of additional flour.

Divide the dough into two portions and shape each into a rectangle approximately 1½ inches thick. Wrap each portion tightly in plastic wrap and refrigerate overnight.

Preheat the oven to 425°F (220°C). Line two large baking sheets with parchment paper or lightly coat with nonstick spray.

On a generously floured surface, roll one portion of dough to a ¼-inch thickness. Using a 2½-inch round cookie cutter, cut out circles and place them on the prepared baking sheets, spacing evenly.

Bake the cookies for 7 to 8 minutes, or until the bottoms are just beginning to turn golden. The tops should remain pale. Transfer cookies immediately to a wire rack to cool completely.

In a clean mixing bowl, cream the butter and vanilla extract together. Gradually add the powdered sugar, beating until smooth. Add the heavy cream one tablespoon at a time until the frosting reaches the desired consistency. If using, add food coloring and mix until well incorporated.

Once the cookies are fully cooled, frost generously and top with sprinkles. Allow the frosting to set before storing.