Preheat & Line Pan: Preheat oven to 350°F (175°C). Grease an 11x15-inch or standard half-sheet jelly roll pan with nonstick baking spray, lining with parchment paper for effortless lifting.

Whisk Dry Ingredients: In a medium bowl, whisk together all-purpose flour, baking powder, baking soda, ground cinnamon, pumpkin pie spice, and sea salt.

Beat Wet Ingredients: In a large stand mixer bowl or with a hand mixer, beat eggs, granulated sugar, brown sugar, oil, pumpkin puree, and vanilla extract on medium speed for 2 minutes until light, voluminous, and glossy.

Fold Batter: Add dry ingredients into wet ingredients. Fold gently with a spatula just until thoroughly incorporated. Do not overbeat.

Spread & Bake: Pour batter into prepared jelly roll pan and smooth evenly with an offset spatula. Bake for 22 to 26 minutes until a toothpick inserted in the center comes out clean and the cake springs back lightly when pressed. Cool completely on a wire rack for 45 minutes.

Whip Frosting: In a clean mixer bowl, beat softened cream cheese and butter for 3 minutes until pale and creamy. Add powdered sugar, vanilla extract, and salt. Beat on low until combined, then whip on high for 2 minutes until cloud-like and fluffy.

Spread & Slice: Spread thick cream cheese frosting evenly over cooled pumpkin sheet cake using an offset spatula. Dust with extra cinnamon and scatter toasted chopped pecans. Slice into 24 bars and serve chilled or room temperature!