Preheat the oven to 350°F (180°C). Smear a little butter on the sides and bottom of a 9x13-inch baking pan.
In a small microwave-safe container, melt the 6 tablespoons melted butter using 50% power in the microwave.
In a large bowl, whisk the 2 large eggs. Slowly pour the melted butter into the egg whisking constantly.
Add the 2 cups sourdough discard, 2 cups buttermilk, and ¼ cup granulated white sugar. Whisk to combine.
Add the 3 cups all-purpose flour, 2 teaspoons baking powder, 1 teaspoon baking soda, and ½ 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.
Pour the batter into your prepared pan and spread evenly. Allow the batter to rest for 15 minutes.
Bake for 20 to 25 minutes, or until a toothpick inserted in the center comes out clean.
Let the pancakes cool for 5 minutes before slicing into squares or rectangles. Serve warm with syrup, fresh fruit, or whipped cream.
Notes
Use room temperature ingredients to help the batter mix more evenly.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.The secret to fluffy pancakes is to not over-mix the batter. Overmixing causes too much gluten to form creating tough chewy pancakes.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.Storage: Leftover pancakes can be stored in the refrigerator for up to five days. Reheat the pancakes in the microwave.