Line a baking sheet with parchment, and put about ⅓ cup sugar in a shallow bowl. Set aside.
Preheat oven to 350 degrees F.
Fix KitchenAid with paddle attachment (You can also use a hand mixer) and mix butter 20-30 seconds until soft.
Add oil and mix about a minute. Depending on how soft the butter is, it might all come together or you could have some pieces of butter - that is OK.
Add egg, sour cream, sugar, and almond and vanilla extracts.
Mix on low-medium until well combined.
Add flour, baking powder, and salt. ***To measure flour, stir, scoop into a measuring cup, and level off with the flat side of a knife.
Mix just until the dough comes together and is smooth and everything is combined.
Scoop generous about 2 tablespoons of dough onto prepared cookie sheet, keeping the cookies 2-3 inches apart.
Spray the bottom of a glass or jar with cooking spray before dipping in sugar for the first time (so the sugar sticks to the bottom of the glass).
Press the glass down on a cookie while twisting slightly (this will give the cookies the classic jagged edge). The glass should make a slight indent in the center of the cookie.
Repeat with remaining balls of dough on the cookie sheet, then bake for 8-9 minutes. The cookies will not brown, and should be slightly soft to the touch but not doughy.
Allow the cookies to cool on the baking sheet for a few minutes, then remove to a wire rack. Allow all cookies to cool completely before frosting.
FOR THE FROSTING:
Mix butter until soft and creamy.
Add sour cream and vanilla, and mix until smooth.
Add powdered sugar and mix until smooth and creamy.
Add a few drops of food coloring to make the frosting any color you want.
SERVING & STORING:
Swig cookies are SO much better when served cold! Plan ahead and refrigerate the cookies after you have frosted them. Leave them in the fridge at least hour, or if you're in a hurry you can pop them in the freezer for 30-45 minutes.
Store these cookies in an airtight container (separate layers with parchment or wax paper) in the fridge for up to 2 weeks.
Store in the freezer up to 1 month. Thaw in the fridge for a few hours before serving.
Notes
I used Better Batter gluten free flour for this recipe. It is my favorite all-purpose gluten free blend and works great for cookies! Because gluten free flours behave differently, I don't know what the results will be if you use a different flour.