Preheat your oven to 400°F. Add flour, granulated sugar, baking powder, baking soda, and salt to a medium bowl, and whisk to combine.
1.5 cups all-purpose flour, 0.5 Tablespoons granulated sugar, 1 teaspoon baking powder, 0.25 teaspoons kosher salt, 0.25 teaspoons baking soda
Cube cold butter and add it to the flour mixture. Toss to coat the butter pieces with flour, then rub the butter into the flour until coarse crumbs form. Work quickly, so the butter does not melt.
0.75 cups salted butter
Mix egg, plain Greek yogurt, and milk in a small bowl to combine.
0.5 cups plain greek yogurt, 3 Tablespoons milk, 1 large egg
Form a well in the middle of the flour mixture. Add the liquid mixture to the well.
Mix the liquid mixture with the dry mixture until a wet dough is formed.
Using a 2 ounce ice cream scoop or a spoon, portion the dough onto a parchment-lined baking sheet. Divide the dough into 8 biscuits.
Bake at 400°F for 15-17 minutes, or until the biscuits are cooked through and golden-brown on top. Transfer to a wire rack to cool completely.