Add the pumpkin puree, eggs, almond milk, vanilla extract, maple syrup, oats, baking powder, cinnamon, allspice, nutmeg, ginger, and salt to your blender. Blend on high for about 30 to 60 seconds, until the mixture looks completely smooth with no visible oat flecks. The batter will be noticeably thick, closer to a muffin batter than a traditional pancake batter, and it will continue thickening the longer it sits.
Lightly coat a griddle or non-stick skillet with olive oil and place it over medium heat. Give the pan a minute or two to heat through evenly before adding any batter, since a griddle that's too cool will leave your pancakes pale and a little gummy in the middle. You'll know it's ready when a drop of water sizzles on contact.
Scoop about ⅓ cup of batter onto the griddle for each pancake, then use the back of your spatula to gently spread it out, since the thick batter won't pour or spread on its own. Cook for 2 to 4 minutes, watching for the edges to look set and a few small bubbles to form across the surface. That's your cue that the underside is ready.
Slide your spatula underneath and flip each pancake, then cook for another 2 to 3 minutes until the second side turns a deep golden brown. If pancakes are browning faster than the centers are cooking, lower the heat slightly; I usually start on medium and drop to medium-low halfway through the batch.
Move the finished pancakes to a plate and repeat with the remaining batter, adding a little more oil to the griddle between batches if needed. Serve them right away while they're still warm and slightly soft in the center.