In a large bowl, combine the flour, protein powder, baking powder, and salt.

Make a well in the middle and pour the milk, egg, butter, and vanilla (if using). Break up the eggs with a fork first, then incorporate them into the other liquid ingredients (you could do this in a separate bowl, but why dirty another thing). Mix the batter, working the dry ingredients from the outside-of-the-bowl-in, until there are no visible lumps.

Heat a large non-stick pan (or griddle) over medium-high heat. Once hot, grease the surface with butter, oil, or spray. Immediately, pour ¼ cup of pancake batter onto the greased pan. Use the back of the spoon to spread it out, it's a thick batter.

Cook the pancakes for about 2 minutes, until the edges begin to look defined and bubbles form. Flip the pancakes over and cook for another two minutes. Avoid pressing down with a spatula. Remove the pancakes from the pan onto a plate. Repeat the process with the remaining pancake batter.

Serve them immediately or keep them warm. Then, stack them up, and top them with your favorite toppings and syrup.

Refrigerate unused batter, covered, for up to 2 days. Let it come to room temperature on the counter before cooking. Cold batter is thick and difficult to pour. Store leftover cooked pancakes for up to 3 days in the fridge in an airtight container, or freeze for up to 3 months.