Using a fork, pastry blender, or stand mixer, cut the butter into the flour mixture until the butter is incorporated well. The mixture will be course and crumbly.
Add in the beaten eggs and slowly add in buttermilk as you stir. When dough is completely blended it should be soft and slightly fluffy.
Flip dough onto a floured work surface and roll out until it's about 3/4 inch thick.
Use a biscuit cutter or the top of a mason jar to cut out biscuits.
Place biscuits in a greased cast iron skillet or other oven-proof dish. Just be sure to place biscuits close together.
Bake 15 minutes until fluffy and golden brown.
Optional: Melt 1 tablespoon of butter and brush over the tops of the biscuits in the final few minutes of baking.
Notes
Note: I do not suggest substituting other gluten-free flours or using regular milk in place of buttermilk.