Preheat the oven to 350°F (175°C). Lightly grease a 10-inch (25 cm) cast-iron skillet with butter or nonstick cooking spray.
cooking spray
In a large mixing bowl, whisk together the pumpkin purée, brown sugar, granulated sugar, eggs, evaporated milk, vanilla extract, pumpkin pie spice, cinnamon, and salt until smooth and evenly incorporated, with no visible streaks of egg.
1 (15-oz / 425 g) can pumpkin purée, ½ cup (107 g) packed dark brown sugar, ¼ cup (50 g) granulated sugar, 2 large eggs, 1 cup (240 ml) evaporated milk, 1 tsp (5 ml) vanilla extract, 1½ tsps (3 g) pumpkin pie spice, ½ tsp (1.3 g) ground cinnamon, ¼ tsp (1.5 g) table salt
Pour the pumpkin mixture into the prepared skillet and spread evenly.
In a separate bowl, stir together the old-fashioned oats, all-purpose flour, brown sugar, cinnamon, and salt. Add the cold, cubed butter and use a pastry cutter or fork to work it into the dry ingredients until the mixture forms coarse, irregular clusters with no large chunks of butter remaining.
1 cup (90 g) old-fashioned rolled oats, ¾ cup (90 g) all-purpose flour, ¾ cup (160 g) packed dark brown sugar, 1 tsp (2.6 g) ground cinnamon, pinch of salt, ½ cup (113 g) cold unsalted butter
Stir the chopped pecans into the oat mixture until evenly distributed. Scatter the topping over the pumpkin filling, covering the surface without pressing it into the filling.
½ cup (55 g) chopped pecans
Bake for 40–45 minutes, or until the oat and pecan topping is golden brown and the pumpkin filling is mostly set. The center should have a slight jiggle when the skillet is moved, but it should not appear liquid. If the topping begins browning too quickly before the filling is ready, loosely cover the skillet with aluminum foil.
Remove the skillet from the oven and let the pumpkin crisp rest for 10–15 minutes. The custard filling will continue to firm as it coolls, making it easier to spoon into serving bowls. Serve warm with vanilla ice cream or whipped cream, if desired.
vanilla ice cream, whipped cream