Melt the butter in the microwave for 20-30 seconds or over the stove top. Set it aside to cool down. Take the oat milk and applesauce out of the refrigerator so that they start to come to room temperature.
In a large bowl, whisk together the dry ingredients (flour, sugar, baking powder, baking soda, and salt). In a small bowl, combine the wet ingredients (oat milk, melted butter, applesauce, and vanilla extract). Pour this mixture into the dry-ingredient bowl.
Gently stir the batter together just until you don’t see any streaks of flour. Lumps in the batter are okay as they will dissipate with time. Note: Since the consistency of oat milk can vary, you may need to add a little more of it if the batter is too thick and hard to stir through. If the batter is on the thin and runny side, mix in some more flour.
Heat a nonstick pan or griddle to slightly below medium heat. Coat the pan with a thin layer of butter when the pan is fully heated. Pour ⅓ cup of the pancake batter into the pan. Add more pancakes to the pan if space permits.
Let them cook for 3-4 minutes. Flip the pancakes with a very thin turner once you see bubbles coming to the surface and popping. Cook them for another 1-2 minutes and then move them over to a cooling rack or serving plates.
Add a little bit more butter to the pan and repeat these steps until you’ve used up all of the pancake batter. You may need to lower the heat as you go because the pan can get hotter over time.