Preheat your oven to 350°F and position a rack in the center. While the oven heats, lightly grease or line a 9×13-inch baking pan with parchment paper for easy removal. This gives you time to complete your mise en place while the oven reaches temperature, and the parchment paper makes removing these bars cleanly much easier.

In a medium bowl, whisk together the flour, ground cinnamon, baking powder, baking soda, and salt. Whisk thoroughly for about 30 seconds to ensure the leavening agents are evenly distributed throughout the flour—this prevents dense pockets in your finished bars. Set this dry mixture aside.

In a large bowl, beat the room-temperature eggs for about 1 minute until they’re slightly foamy. Add the granulated sugar and packed brown sugar, then beat for another minute until the mixture is light and well combined. I like to add the sugars to the eggs first because beating them together creates a slightly lighter crumb structure in the final bars. Now add the pumpkin puree and unsweetened applesauce, stirring gently with a spatula until fully incorporated and smooth.

Pour the dry ingredient mixture from Step 2 directly into the wet mixture from Step 3. Using a spatula or wooden spoon, gently fold the ingredients together until just combined—do not overmix. A few small streaks of flour are perfectly fine; overmixing will lead to tough, dense bars instead of a tender crumb. The batter should be thick but pourable.

Pour the batter into your prepared 9×13-inch pan and smooth the top gently with a spatula. Bake for 25-30 minutes, until a toothpick inserted into the center comes out with just a few moist crumbs (not wet batter). The bars should be set around the edges but still slightly tender in the middle. Let the bars cool completely in the pan on a wire rack or countertop—this is important because they’ll firm up as they cool. Once cooled, you can cut them into squares and serve.