In a large bowl whisk together dry ingredients.
In an electric mixer beat the butter and sugar until light and fluffy, 2-3 minutes.
Add egg yolk and vanilla, mix until combined.
On low speed gradually add the dry mixture just until combined. Transfer the dough to a lightly floured surface and shape into a ball. Divide the dough in half onto 2 pieces of wax paper/parchment. Flatten each one into a disk. Cover with the waxed paper and refrigerate for 30 minutes or overnight.
Preheat oven to 350Β°F and prepare baking sheets.
Gently roll out dough to ΒΌ-inch thickness, sprinkling with flour only when needed.*
Cut shapes and transfer cookies to baking sheets. Refrigerate 10-15 minutes before baking.
Gather remaining pieces of dough from cut cookies, gather into dough ball and repeat as before. Refrigerate dough 10-15 minutes before rolling out again.
Bake cookies in preheated oven for 12-14 minutes or until just turning golden on the edges.
Allow to cool on the baking sheet for 2-5 minutes before transferring to wire racks to cool completely.
Decorate as desired. Store cookies in an airtight container.