Prep the pan: Heat your oven to 350°F (175°C). Line an 8x8-inch pan with parchment, leaving a little overhang for easy lifting.
Lightly grease the sides.
Mix the dry ingredients: In a large bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 3/4 cup granulated erythritol/monk fruit, 1 teaspoon baking powder, 1 teaspoon cream of tartar, 1 1/2 teaspoons cinnamon, 1 teaspoon pumpkin pie spice, and 1/2 teaspoon salt. Break up any almond flour clumps.
Combine the wet ingredients: In a separate bowl, whisk 2 large eggs, 1 cup pumpkin puree, 1/3 cup melted butter (slightly cooled), and 2 teaspoons vanilla until smooth.
Bring it together: Pour the wet mixture into the dry. Stir with a spatula until just combined.
The batter will be thick but spreadable. If using, fold in 1/2 cup sugar-free chocolate chips or 1/2 cup chopped pecans.
Make the topping: Mix 2 tablespoons granulated erythritol/monk fruit with 1 teaspoon cinnamon.
Spread and sprinkle: Scoop the batter into the prepared pan and smooth the top. Sprinkle the cinnamon “sugar” evenly over the surface.
Bake: Bake for 22–28 minutes, until the edges are set and a tester comes out with a few moist crumbs.
Do not overbake—these are best soft.
Cool completely: Let the bars cool in the pan for at least 30–45 minutes. Lift out using the parchment and set on a rack to finish cooling before slicing.
Slice and serve: Cut into 12–16 bars. Enjoy as-is, or add a dollop of lightly sweetened whipped cream.