Preheat the oven to 350 degrees Fahrenheit and line an 8-inch square baking pan with parchment paper. If you don't have parchment paper, spray the baking dish with cooking spray or grease it with coconut oil.
Combine the pureed pumpkin, pure maple syrup, and almond butter in a large bowl and mix well until a thick, creamy wet mixture forms.
Add the rolled oats, pumpkin pie spice, and sea salt to the mixing bowl and mix until a thick, sticky dough forms.
Mix in the chopped Granny Smith apple until it is well-distributed throughout the dough.
Spread the pumpkin apple oatmeal bar mixture into the prepared baking dish using a rubber spatula and bake for 30 to 35 minutes, or until the edges are golden brown and the center tests clean.
Allow the apple bars to cool to room temperature before slicing and serving.
