1-First, preheat your oven to 350°F (175°C) and center the rack, then prepare an 8-inch square pan by spraying or lining it for easy release. This step sets the stage for even baking and helps with high altitude adjustments.

2-Melt the unsalted butter in a saucepan over medium heat, cooking it for 5-10 minutes until it turns golden brown and develops a nutty aroma; let it cool for 10 minutes before using. In a large bowl, whisk together the pumpkin puree, light brown sugar, granulated sugar, large eggs, whole milk, apple cider vinegar, vanilla extract, and the cooled brown butter to create a smooth wet mix.

3-Next, sift the all-purpose flour, baking soda, coarse kosher salt, ground cinnamon, ground ginger, ground cloves, and ground nutmeg into another bowl. Add the dry ingredients to the wet mix and whisk until just combined, then gently fold in the semi-sweet chocolate chips. Pour the batter into your prepared pan and bake for 28-30 minutes, or until a toothpick inserted in the center comes out clean and the top springs back when touched; let it cool completely afterward.

4-For the buttercream, beat the softened unsalted butter until smooth, about 1 minute. On low speed, mix in the powdered sugar, unsweetened cocoa powder, meringue powder if you’re using it, and coarse kosher salt until combined. Add the vanilla extract and beat on medium speed for 3-4 minutes until fluffy, adding 1-2 tablespoons of milk if needed to reach the right consistency.

5-Once your cake is cool, frost it evenly and, if you like, dollop spiced pumpkin butter on top and swirl it gently for a fun twist. This high altitude pumpkin chocolate chip cake recipe is ready in just 50 minutes total, with 20 minutes prep and 30 minutes cook time.