In a large bowl, whisk together flour, sugar, baking powder, and salt.
In a separate medium bowl, whisk eggs with milk and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until they’re just combined, taking care not to over-mix. Some lumps are OK. Let batter rest for 5-10 minutes.
Heat a griddle or skillet over medium heat and brush lightly with a little butter or cooking spray. Pour about ⅓ cup of batter onto it and sprinkle some M&Ms over the top of the pancake batter. Cook for about 2 minutes, until bubbles start to form on the surface and then flip and cook for another minute, until golden brown.
Serve pancakes with whipped cream and more M&Ms sprinkled over the top.