Preheat your oven to 350°F (175°C) to ensure even baking and perfect rise.
In a large mixing bowl, beat the softened butter and granulated sugar together with an electric mixer on medium speed for 2-3 minutes until light and fluffy.
Add the room temperature eggs, sour cream, vanilla extract, and almond extract to the butter mixture and mix until well combined, scraping down the bowl as needed.
In a separate bowl, whisk together the all-purpose flour, cornstarch, baking powder, baking soda, cream of tartar, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Avoid overmixing to keep cookies tender.
Use a cookie scoop to portion dough onto a parchment-lined baking sheet, leaving space between cookies for spreading.
Bake in the preheated oven for 10-12 minutes until edges are set and tops are slightly puffy. Remove from oven and let cool on the baking sheet for 5 minutes.
Transfer cookies to a wire rack to cool completely.
For the frosting, beat together softened butter, powdered sugar, vanilla extract, and heavy whipping cream until smooth and creamy. Add food coloring if desired.
Once cookies are completely cool, generously frost each cookie. Decorate as desired with sprinkles or other toppings.