The Bojon Gourmet

Prepare things
1 Position a rack in the center of the oven and preheat it to 350ºF.
11 Lightly butter an 8-inch square pan with 1 teaspoon soft butter. Line the pan with parchment paper on all sides.
Make the batter
2 Combine the softened butter and brown sugar in a stand mixer fitted with the paddle attachment. Beat on medium speed until light and fluffy, 2-3 minutes, scraping down the sides of the bowl as needed.
3 Add the eggs one at a time, beating to combine after each addition, and scraping down the sides of the bowl as needed. It’s ok if the mixture looks curdled; it will come together in the next step.
4 Meanwhile, stir together the crème fraiche and pumpkin puree in a measuring cup.
5 Sift or whisk the almond, oat, sweet rice, and tapioca flours into a medium bowl along with the baking powder, baking soda, pumpkin pie spice, and salt, adding back anything left in the sifter.
6 Add half of the flour mixture to the butter mixture and beat on low speed until it’s mostly incorporated. Scrape down the sides of the bowl. Add the pumpkin mixture and beat on low until just incorporated. Add the remaining flour mixture and beat on low speed until incorporated. Scrape the sides of the bowl and the paddle once more, then beat the batter on medium speed until light, airy, and smooth, 15 seconds.
Bake
7 Spread the batter into the prepared pan, smoothing the top, and bake at 350ºF until a tester inserted comes out with a few moist crumbs, 40-55 minutes. An instant-read thermometer inserted near the center should register around 190ºF.
8 Let the cake cool completely.
Serve
14 To serve the cake, lift the cake out of the pan, invert onto a serving platter, and peel away the parchment.
15 Top the cake with swirls of brown butter cream cheese frosting or other favorite topping. 
Storage
17 Store the cake, covered, at cool room temperature for up to 24 hours, in the fridge for up to 5 days, or freeze for up to several months. The cake is best at room temperature so the frosting will be soft.