Add 1 cup vegetable shortening and 1 cup granulated sugar to a large bowl and beat with a hand mixer until light and fluffy.

Add 1 teaspoon vanilla extract, ½ cup + 1 tablespoon sour cream, and 2 large eggs and beat until well combined. 

In a separate large bowl, sift together 4 cups all-purpose flour, ½ teaspoon baking soda, and ½ teaspoon kosher salt.

Slowly add dry ingredients to wet, mixing with a wooden spoon until no flour is visible.

Dump the dough onto a floured surface, shape into a disk, and cover with plastic wrap. Refrigerate for 30 minutes. 

Preheat oven to 350 degrees. Line three baking sheets with parchment paper. 

Remove dough from the refrigerator, unwrap it, and place on a lightly floured surface. 

Using a rolling pin, roll out until approximately ⅜-inch thick. Cut using a 3½-inch star-shaped cookie cutter and place the stars on the prepared baking sheets. 

Combine the dough scraps into a ball and repeat rolling out and cutting until most of the dough is used. 

Bake for 10-12 minutes – the edges should take on the slightest color and the bottoms, golden brown. Remove to a wire rack to cool completely.