A week on Swan’s Island is never enough time. It simply isn’t. Yes, there’s relaxing and hiking and quiet, but just when you start to fully decompress, you have to get back on the ferry, drive ten hours, and return to your real life. It’s the worst.We keep saying “two weeks next year” but only getting half of that. I’m putting it out to the universe now: one month next year. That way, when we only get half, it’ll be two weeks. Am I trying to con the universe in to more vacation? Sure, why not. You can’t blame me for wanting to spend time with the friends we’ve made up there (even socially distanced) instead of carrying on entire relationships via Facebook.I mean, would you believe that I’ve pretty much never baked for anyone on Swan’s Island? It’s true. I’ve been going there regularly for the last six years, made some friends, and know the people who own the general store well enough that they recognized me immediately with my mask on, but I’ve never really baked for any of them. They know, of course, that I bake and blog, and I always say I’m going to make something for them, but then time gets away and suddenly I’m on the ferry back to the mainland.All that said, when we booked our trip in July, I decided this year was *the* year. I tested a recipe before I left Brooklyn, brought a box of potato starch and the vegan butter I like, and it took until the second-to-last day, but I baked this Pumpkin Sheet Cake with Maple Frosting for my Maine people. Finally.I’ve never put a sheet cake on here. It’s not because I think they’re “less than” or something—I just have occasions for other configurations of cake and frosting far more frequently than I do for this super simple slice-and-share situation. But our annual Swan’s Island trip? That’s a slice-and-share situation if I’ve ever seen one. Especially in COVID, when get-togethers with people outside my immediate germ pod aren’t a thing, it was so nice to be able to wrap up and dole out slices of this Pumpkin Sheet Cake with Maple Frosting without having to worry about keeping layers intact.As with most of what we eat on Swan’s Island, this cake was made with my trusty co-traveler/fellow Maine enthusiast, VJ, in mind. I’ve mentioned many times that she is a gluten-free vegan, and though I am not either of those things, I greatly enjoy the challenges and rewards of baking (and cooking) that way when we are together. It’s far more fun to bake when people can eat what you make…not that I’d be particularly mad about being saddled with all 15 slices of this cake. I mean, do you see that vegan Maple Frosting???The pumpkin cake is a variation on the vegan, gluten-free chocolate cake I posted last year. It relies primarily on almond flour, potato starch and cornstarch for structure, and pumpkin purée and pumpkin pie spice for flavor. There are other things in the batter too, of course (granulated and brown sugars, vanilla, leaveners, almond milk), and they all bake up into a moist, tender, nicely-spiced sheet of cake. Vegan and gluten-free or not, this pumpkin cake is legit.Believe me when I tell you that I understand wanting to eat this cake by its lonesome straight out of the oven, or with a simple dusting of confectioner’s sugar…but also? Believe me when I tell you that a swoopy layer of Maple Frosting takes this seasonal dessert from very good to fabulous. For real.Pumpkin Sheet Cake with Maple Frosting is very good the day it’s made, but as with many pumpkin spice things, it’s actually more delicious the next day, after the flavors have melded. But with a cake this good around, I can’t blame anyone for not waiting to dig in. I mean, I certainly didn’t.

Pumpkin Sheet Cake with Maple Frosting {Vegan & Gluten-Free}
makes a single layer 9×13-inch sheet cake

2 teaspoons apple cider vinegar
~1 1/4 cups unsweetened almond milk
1/3 cup pure pumpkin purée
2 teaspoons pure vanilla extract
2 1/2 cups blanched almond flour (not almond meal)
3/4 cup potato starch
1/4 cup cornstarch
1/2 cup granulated sugar
1/2 cup light brown sugar, packed
2 1/4 teaspoons pumpkin pie spice
1 1/8 teaspoons baking powder
1 1/8 teaspoons baking soda
1/4 teaspoon Kosher or sea salt

For finishing:
Vegan Maple Frosting (recipe below)
sprinkle of ground cinnamon (optional)

Preheat oven to 350F. Grease a 9×13-inch cake pan. Line with parchment and grease again. Set aside.

Pour apple cider vinegar into a liquid measuring cup. Add almond milk until liquid reaches the 1 1/4 cup mark. Stir and let sit for 5-10 minutes, until curdled. Stir in pumpkin purée and vanilla. Set aside.

In a large mixing bowl, whisk together blanched almond flour, potato starch, cornstarch, granulated sugar, light brown sugar, pumpkin pie spice, baking powder, baking soda, and salt. Add liquid ingredients in two installments, whisking until combined.

Transfer batter to prepared pan and smooth to the edges with a silicone spatula or wooden spoon. Tap pan on the counter 5 times to release any large air bubbles. Transfer to the oven and bake 32-35 minutes, or until a toothpick inserted in the center of each layer comes out with only a few crumbs.

Let cake cool completely in its pan on a cooling rack. Run a thin knife along the edges of the pan before inverting to release onto a platter (alternatively, you may keep it in the pan and serve from there). Frost as desired with Vegan Maple Frosting (recipe below). Sprinkle with cinnamon, if desired.

Frosted cake will keep at room temperature for up to 3 days and refrigerated for up to 4. Unfrosted cake may be triple-wrapped in plastic wrap and frozen for up to 1 month. Thaw overnight in the refrigerator before frosting.

Vegan Maple Frosting
makes enough for the top of one sheet cake

4 ounces (1/2 cup) vegan butter, room temperature (I like Miyoko’s)
2 ounces (1/4 cup) shortening, room temperature (I like Nutiva)
1 1/2 cups confectioners sugar
pinch of Kosher or sea salt
2 teaspoons pure vanilla extract
2 tablespoons pure maple syrup

In a large mixing bowl, use an electric mixer to beat vegan butter and shortening until light and fluffy. Mix in confectioners sugar in two installments, mixing until combined and fluffy. Mix in salt, followed by vanilla and maple syrup.

Use to frost the top of the sheet cake.