In a small microwave-safe container, melt the 3 tablespoons melted butter using 50% power in the microwave.
In a large bowl, whisk the 1 large egg. Slowly pour the melted butter into the egg whisking constantly.
Add the 1 cup sourdough discard, 1 cup buttermilk, and 2 tablespoons granulated white sugar. Whisk to combine.
Add the 1 ¼ cups all-purpose flour, 2 teaspoons baking powder, ½ teaspoon baking soda, and ¼ teaspoon kosher salt to a sifter. Sift the dry ingredients into the wet ingredients.
Fold the dry ingredients into the wet ingredients, until just combined do not overmix.Allow the batter to rest for 15 minutes. Resting the batter allows the flour to absorb more moisture creating softer pancakes.
Heat a griddle or large nonstick skillet over medium-low heat. Lightly butter or oil the griddle or skillet.Once the griddle or skillet is hot, drop ¼ cupful of the batter into the pan. Cook for 3 to 4 minutes, until the pancakes look dry and bubbles form on the top.
Flip and cook on the other side for 1 to 2 minutes. If desired, transfer the pancakes to a baking sheet and keep them warm in the oven while you cook the remaining batter.
Notes
Make sure your baking powder is fresh. Old expired baking powder will create flat pancakes. Baking powder has a shelf life of 9-12 months. Usually, there is an expiration date printed on the canister. To test your baking powder add a teaspoon of baking powder to a glass of hot water. If it starts to fizz it is still good.Don't skip the resting time for the batter. Resting the batter allows it to fully hydrate and gives the baking soda and baking powder time to start reacting leading to fluffier pancakes.An electric griddle is my favorite way to cook pancakes because I can cook nine pancakes at one time. If you don't have a griddle the pancakes can easily be cooked in a skillet on your stovetop.Be patient when cooking pancakes. Don’t rush them on high heat, or flip them too early.Keep cooked pancakes warm on a sheet pan in a 170°F (77°C) oven.Storage: Leftover pancakes can be stored in the refrigerator for up to five days. Reheat the pancakes in the toaster or microwave.