These Pumpkin Crumble Bars are an easy, beloved fall dessert! A delicious oat crumble doubles as the crust and crumb topping, sandwiched around a sweet, creamy pumpkin filling.
Preheat oven to 350 degrees. Liberally grease a 9x9-inch baking pan with olive oil or butter (or line with parchment paper).
Combine crumble ingredients using a pastry cutter (or even a fork!) to cut the cold butter into the other ingredients until the mixture is even with pea-sized pieces of butter. Place half the crumble mixture in the bottom of the baking pan and press firmly down. Reserve the other half of the crumble mixture.
Combine filling ingredients. Pour pumpkin filling over the crumble mixture pressed down in the baking pan. Sprinkle (don't pan!) remaining crumble on top of the pumpkin filling.
Bake for 35-45 minutes. Allow to cool for one hour at room temperature, and when cool enough transfer to the fridge to cool another two hours. Leave bars refrigerated until serving. Enjoy!