Mix the wet ingredients in a large bowl until smooth: milk, pumpkin puree, egg, oil, and lemon juice.
Whisk the dry ingredients together in a medium-sized bowl: flour, light brown sugar, baking powder, baking soda, pumpkin pie spice, and a pinch of salt.
Add the dry ingredients to the wet. Mix using a wooden spoon until just combined. Make sure not to overmix the batter.
Let the batter rest for 5 minutes.
Heat a skillet or griddle over medium-low heat. Add butter or cooking spray. Pour about ⅓ cup of batter into the hot skillet. Cook until the edges start to brown and bubbles appear all over the surface. Using a spatula, flip the pancakes over and cook for 1-2 minutes on the other side.