Preheat your oven to 175°C (350°F). Grease a 9x13 inch baking pan and set aside.
In a large mixing bowl, whisk together the flour, cinnamon, nutmeg, baking powder, and salt until evenly combined.
In another bowl, stir together the canned pumpkin, brown sugar, melted butter, and eggs until the mixture is smooth and slightly frothy, filling your kitchen with warm pumpkin spice aroma.
Gradually fold the dry ingredients into the wet mixture using a spatula, just until combined. The batter will be thick and a bit lumpy—embrace the rustic texture.
Pour the batter into your prepared pan, spreading it evenly with the spatula. Press it gently into the corners for a rustic but even layer.
Bake for 25 to 30 minutes, until the edges are golden and a toothpick inserted into the center comes out with moist crumbs. Your kitchen will smell cozy and spicy!
While the bars cool slightly, prepare your frosting by beating softened cream cheese, powdered sugar, and vanilla until smooth and creamy. Chill if needed.
Once the bars have cooled for about 15 minutes, spread the cream cheese frosting evenly over the top, creating a tangy, creamy layer that complements the warm spices.
Let the frosted bars rest for another 10 minutes to set the frosting, then use a sharp knife or bench scraper to cut into squares. Serve warm or at room temperature for the ultimate fall treat.
Enjoy each messy, comforting bite—a perfect blend of gooey pumpkin filling, crumbly edges, and tangy frosting that embodies cozy fall days.
