Buttermilk makes a good milk substitute, especially in pancakes and waffles. It reacts a little bit differently to baking powder than cow's milk does, so it requires mild adjustments to recipes. Because Bisquick mix is a specific recipe, some of the adjustments are a little harder to figure out, but the recipes still allow for some substitutions. The adjustments are simple with the right techniques.
Measure 2 cups of Bisquick mix. Make sure the top of the mix is flush with the top of the measuring cup and scrape off the extra with a knife. Pour the 2 cups of mix into a bowl.
Add 1 tsp. baking soda, 1 3/4 cups buttermilk and one egg. Bisquick uses baking powder to react with milk and eggs to create the bubbles in pancakes and make them fluffy. Buttermilk reacts differently with the ingredients in baking powder, which are baking soda and cream of tartar, so you need less egg and a little bit more buttermilk and baking soda to create the same reaction.
Wisk all of the ingredients thoroughly so there are no lumps and the mixture is smooth.
Use a 1/4-cup measuring cup to measure out each pancake onto the griddle. Cook them until the edges are dry and bubbles rise from the middle. Turn them with a spatula and let them cook until the bottom is golden brown.