Preheat your oven to 350 degrees Fahrenheit. It’s crucial to have the oven hot before you put the cake in to ensure proper rising.
In a large mixing bowl, sift together the powdered sugar, Pamela's Gluten Free Artisan Flour Blend, salt, ground cinnamon, ground ginger, ground nutmeg, and ground cloves. Sifting helps to aerate the mixture, ensuring a light and fluffy cake. You might want to do this step about three to four times to get the best results.
In a stand mixer fitted with a whisk attachment, add the large egg whites, cream of tartar, and vanilla. Beat this mix on medium-high speed until it froths.
Once it froths, slowly add in the organic sugar while continuing to beat the egg whites. After about five minutes, you should notice that soft peaks are forming.
Next, turn the mixer speed to high and continue beating until the peaks become stiff and glossy. This is where the magic happens; the egg whites will transform into a beautiful meringue.
Transfer the whipped meringue into a large wide bowl. This allows for easy folding in of the flour mixture and pumpkin puree.
Gently add the flour mixture and pumpkin puree in about four different batches. Use a rubber spatula to fold these ingredients in gently, taking care not to deflate the meringue. It’s okay if there are a few pockets of pumpkin throughout the batter.
Once everything is evenly incorporated, pour the batter into a 10-inch ungreased tube pan. Make sure the bottom is lined with parchment paper for easy release.
Smooth the top with a spatula and bake in the preheated oven for 50 minutes. During baking, the cake should rise and become a lovely golden brown.
When the cake is done, it should spring back lightly when touched. Invert the cake pan on a bottle to cool for at least one hour. This step prevents the cake from collapsing.
After cooling, use a long knife to cut around the edges and the center post of the cake to loosen it from the pan. Gently turn the cake upside down, and remove it from the pan. Let it finish cooling on a rack in open air. This cake serves 12 people and is sure to impress!