Preheat oven to 325F. Line a baking tray with parchment paper.
Mix the flours, sugar and salt in a food processor on low for 30 seconds to combine.
Cut the butter into 1/2-inch cubes and toss in a medium bowl with 1/4 cup of the flour mixture.
Return butter and flour to the rest of the flour in the food processor. Mix on low for 3-4 minutes until butter has been incorporated into crumbs. If the mixture starts to clump, stop mixing.
Turn onto a work surface and gently form into a flat dough, about half an inch thick.
You can use a rolling pin or press with the bottom of a glass to flatten the dough.
Using a cookie cutter, cut into rounds. Use a stamp if you have one to form a design!
Use a spatula to move the biscuits to the paper-lined tray. Leave some separation between the rounds in case of spreading.
Bake for 20-25 minutes. Watch the biscuits towards the end of the bake to make sure the edges do not color.