Add the sour cream, eggs and vanilla and continue mixing until well combined. Add in the flour and baking soda mixture, reducing the mixing speed to low just until it is fully incorporated. Do not overmix. If the dough feels too sticky to touch, add a few Tablespoons of flour at a time until you can press the dough without it sticking to your fingers. Be careful not to add too much flour.

Bake in the preheated oven for 10 minutes. Check for doneness by lifting the parchment paper and peeking at the bottom. The cookies should be removed from the oven when they are lightly browned on the bottom but not around the sides. Cool completely before icing.