Put the coconut sugar in a coffee grinder, blender, or small food processor and grind into a fine powder. Although not absolutely essential, skipping this step will result in cookies with a speckled appearance.
Place the ground coconut sugar in a large bowl with the softened butter. Using a hand mixer, cream the butter and sugar together until creamy and lighter in color. About 2-3 minutes.
½ cup unsalted butter, softened, ¼ cup coconut sugar
Add the sour cream, vanilla, and salt. Beat in until fully combined and creamy.
2 TBS sour cream, 1 tsp vanilla, ⅛ tsp table salt
Add the flour to the wet mixture, stirring just until the dough comes together. Be careful not to overmix, as this can make the cookies tough.
1¼ cup white whole wheat flour
Form the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes. Chilling makes the dough easier to roll out and prevents the cookies from spreading too much while baking.
Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper. Take the dough out of the fridge and let warmup slightly to prevent the edges from cracking. Generously flour your work surface and rolling pin, then roll out the dough to about ¼-inch thickness.
Use cookie cutters to cut out shapes. Arrange on the prepared baking sheets, leaving about 1 inch of space between each cookie. Combine scraps into a ball and re-roll up to 2 times.
Bake the cookies for 8-10 minute.
Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely. Once cooled, you can decorate them with icing, sprinkles, or enjoy them plain!