6 tablespoons cold unsalted butter, cut into 1/2-inch pieces
3/4 cup buttermilk, plus more for brushing
Preheat the oven to 375°. In a medium bowl, whisk the 2 cups of flour with the sugar, garam masala, baking powder, salt and baking soda. Using a pastry blender or 2 knives, cut in the butter until it is the size of small peas. Add the 3/4 cup of buttermilk and stir until a dough forms.
Turn the dough out onto a lightly floured surface and knead it 2 or 3 times. Roll or pat the dough into a 6-by-12-inch rectangle, about 3/4-inch thick. Using a floured knife, cut the dough into 8 square biscuits. Brush the tops with buttermilk and transfer the biscuits to a baking sheet. Bake for about 18 minutes, until risen and golden. Transfer to a wire rack to cool.
The biscuits can be stored overnight in an airtight container.