Yes, pancake batter can be refrigerated overnight, and in some cases, this can even improve the texture of the pancakes. Allow the batter to rest in the refrigerator for at least 30 minutes, or up to 24 hours.
Refrigerating pancake batter overnight allows the gluten to relax, resulting in a more tender pancake. The resting period also gives the flour time to fully hydrate, which contributes to a smoother batter and a more even cooking process. Furthermore, the leavening agents (baking powder or baking soda) have time to work, creating a lighter and fluffier pancake. When you're ready to cook, give the batter a gentle stir – but don't overmix it, as this can develop the gluten again and make the pancakes tough. If the batter has thickened too much in the refrigerator, you can add a tablespoon or two of milk to reach the desired consistency.
Don't add any mix-ins like blueberries or chocolate chips to the batter until just before cooking. These ingredients can sink to the bottom of the batter during refrigeration and may affect the overall texture and cooking of the pancakes.