Preheat your griddle or skillet.

In a medium bowl, mix together flour, baking powder, baking soda, salt, and sugar. Set aside.

In another bowl, whisk together milk, egg, vanilla, and nutmeg until blended.

Pour into flour mixture and stir until just mixed; lumps are OK. Whisk in the butter just before cooking.

Pour 2 tablespoons of batter onto the prepared griddle and repeat until you have no more room (about 8 pancakes on a large griddle). Cook until edges start to dry and bubbles are forming on the top, then flip and cook the other side until brown. Repeat until all batter is used.

Place cooked pancakes in a single layer on a baking sheet lined with parchment paper or Silpat liner. Put baking sheet in the freezer for 1 hour, until pancakes have frozen.

Remove baking sheet and stack pancakes in groups of 4, then place inside a freezer-safe container.

To reheat, remove desired amount of pancakes, arrange in a single layer on a plate, and microwave for 45 seconds for 4 pancakes, increasing the time for more pancakes.