Preheat the oven to 375F. Butter a 10.5x7.5” baking pan, 10” cast-iron skillet, or medium casserole dish. Set aside.

In a large bowl, mix together the oats, flour, both sugars, chopped pecans, cinnamon, and salt. Pour in the melted butter, and mix with a fork until fully combined and the mixture resembles a clumpy/crumbly texture. Set aside while you prepare the pumpkin filling.

In a large bowl, whisk together the entire can of pumpkin purée, both sugars, heavy cream, eggs, pumpkin pie spice, salt, and vanilla until well combined and smooth.

Pour the pumpkin filling into the prepared baking pan or skillet. Then, sprinkle the oatmeal pecan crisp topping all over the pumpkin pie mixture.

Bake at 375F for 50-60 minutes, until the filling is set and the crisp topping is golden brown. If the top starts to brown too quickly, tent the top with foil about halfway through baking to prevent from browning too much.

Remove from the oven and let cool for at least 10-15 minutes.

While the crisp is baking, prepare the maple cinnamon brown butter sauce for serving. Add the 4 tbsp (58g) of butter to a saucepan over medium-high heat. Allow to melt and brown, while stirring occasionally (~5-8 minutes). Once the butter smells nutty and has turned golden brown, remove it from the heat and immediately add the maple syrup, cinnamon, and salt. Stir until well combined, then pour into a heat-safe bowl or jar.

Serve the pumpkin pecan crisp warm with a scoop of vanilla ice cream, a drizzle of the maple cinnamon brown butter sauce, and a sprinkle of flaky sea salt, if desired.