Preheat theoven to 400ºF. Line a baking sheet with parchment paper.
In a large bowl, sift together two cups of Bisquick, one-quarter of a teaspoon of baking soda, and two tablespoons of sugar. Cut one-half cup of butter into the Bisquick mixture using a fork or a pastry cutter. Mix until the butter and Bisquick mixture becomes crumbly.
Pour in three-quarters of a cup of buttermilk and stir with a fork just until the dough comes together to form a mass. Do not over-mix.
Gather the dough in the bowl, adding an extra tablespoon of buttermilk if necessary.
Turn out onto alightly Bisquick floured work surface. Pat the dough into a circle. Using atwo-inch round cutter, cut the dough into eight biscuits.
Transfer to theprepared baking sheet. Space the biscuits at least two inches apart.
Lightly brush each biscuit with buttermilk. Sprinkle a pinch of sugar over the top of eachbiscuit if desired.
Bake the biscuits for twenty minutes or until golden. Remove from the oven, transfer to a wire rack to cool, or serve immediately.