Preheat your oven to 350° F. Line an 8-inch springform pan with parchment paper and generally grease the sides (this torte will want to stick!).Cream the butter by adding both the butter and sugar to a large bowl (if using a hand mixer) or the bowl of your stand mixer. Mix on low and slowly increase speed until your sugar is fully incorporated and your butter is light yellow and fluffy.
Add the vegan yogurt and mix on high until fully incorporated (about 30 seconds). Then, sift in the flour and baking powder and mix until a thick batter forms. Spoon the batter into your springform pan and spread it out evenly using the back of a large spoon or an offset spatula.
Place pitted plum halves skin-side up in the batter. Try to avoid getting too close to the edge of the cake, as doing so will make freeing the cake from your pan infinitely harder (I learned that the hard way....). Don't put in too many plum halves close together, as doing so will weigh down your torte and make it more likely to fall apart. You want there to be some space between them. Sprinkle with ground cinnamon and 1 tablespoon of sugar.
Bake in the oven for 60 to 67 minutes (will depend on upon how juicy your plums are), until a toothpick inserted in the center comes out clean. Cool for at least 10 minutes. Then, run a sharp knife around the edge before undoing the spring and freeing the cake from the pan. Allow the cake to cool for another 10 minutes before serving with a dollop of vegan whipped cream or ice cream and slices of fresh plum.
Notes
Please check the Key Ingredients and Substitutions section before asking about substitutions. :)
Because this is a dense torte, it will want to adhere to your springform pan. Accordingly, you MUST line the bottom with parchment paper! Don't skip this!! And make sure to grease the sides!
The batter will be super thick so it'll be a bit like making cobbler. You'll need to spoon it into your pan and spread it out.
I recommend small to medium plums for this recipe. If your plums are too big, they will break up the stability of the cake. If all you got are big plums, I would cut them into smaller pieces, in lieu of just halving them.
Your torte will need time to cool because the plums will be oozing all their juices. If you dive in too early, your torte will fall apart!