Combine the dry ingredients. In a medium bowl, add the flour, baking powder, sugar, and salt. Whisk until the dry ingredients are combined.
Mix the liquids. In a liquid measuring cup or small bowl, add the oat milk, eggs, vegetable oil, and vanilla extract. Mix with a whisk or a fork to fully combine.
Add the wet ingredients to the dry. Pour the wet ingredients into the flour mixture and stir until the batter is just mixed and no streaks of flour remain. The batter should be thick (like a loose pudding), with some lumps, and should easily pour out of a measuring cup.
Heat the pan. Heat 1 tablespoon of vegetable oil in a 10" skillet over medium to medium high heat. To test if the pan is hot enough, add a drop of pancake batter to the pan and listen for a sizzle. If you hear the sizzle, the pan is ready.
Cook the pancakes. Scoop 1/4 cup of the batter onto the preheated skillet and cook for two minutes on one side. The pancakes are ready to flip once they've risen and the top looks bubbly around the edge. *Turn the heat down If the pancakes start cooking too quickly or get too dark in color.
Flip and cook the other side. Carefully flip your pancake and finish cooking the other side for two more minutes. Pancakes are done when they are fluffy, golden brown, and spring back in the middle when poked.
Keep the pancakes warm. Transfer cooked pancakes to a plate or sheet pan and keep warm in a low (200°F) oven until ready to serve.
Cook off the remaining pancake batter. Repeat the scooping and cooking process until the remaining pancake batter is cooked off. You may need to add an additional tablespoon of vegetable oil to the pan in between batches. Once all the pancake batter is cooked, serve with salty vegan butter and maple syrup.