Continue using the bowl you prepared the mix in or dump the stored mix into a large mixing bowl.
Add the milk, egg, and oil and mix until combined but still lumpy. Let the batter rest for 15 minutes before cooking.
¾ cup milk , 1 large egg, 2 tablespoon vegetable or canola oil
Preheat the griddle to 275°F. When ready to cook, coat with cooking spray.
Portion out the batter with a ¼ cup measuring cup onto the hot griddle and cook the pancakes for 2 to 3 minutes, then flip and cook for 1 to 2 additional minutes until golden brown.
Place cooked pancakes on a baking sheet in the oven at 200°F to keep warm until ready to serve.
Serve immediately with butter, syrup, or fresh fruit.