Preheat the oven to 400 degrees F (200 degrees C). Grease a baking sheet.
Mix flour, baking powder, and xanthan gum together in a medium bowl. Cut in butter using a pastry cutter or 2 knives.
Whisk half-and-half, eggs, and egg whites together in a separate medium bowl. Pour over the flour mixture. Add 2 tablespoons basil, 2 tablespoons thyme, garlic, and salt; mix until dough comes together.
Create 6 rounded balls of dough and place on the baking sheet. Sprinkle remaining basil and thyme on top.
Bake in the preheated oven until bottoms and edges turn golden, about 20 minutes.
