• Preheat your oven to 350F. Butter a 9" springform pan.
• In a stand mixer or with electric beaters, cream the butter and sugar until light and fluffy, about 5 minutes. Scrape down the sides of the bowl if necessary. This is going to create a nice light cake.
• Add the eggs, one at a time, letting each become fully incorporated before adding the next. Beat in the vanilla and cinnamon and again scrape down the sides of the bowl.
• Add the baking powder and salt, and mix briefly to combine.
• Add the flour alternating with the Greek yogurt. Blend just until everything is well mixed, don't overdo it.
• Give the mixture a final stir by hand to make sure everything is evenly incorporated, and turn the batter into your prepared pan. Spread out flat with an offset spatula.
• Arrange your apple slices on top of the cake, pushing them into the batter very slightly. I arranged them in a spiral pattern and fit them fairly snugly.
• Bake for about 45-50 minutes, or until the cake is puffed and starting to turn golden on top. I use a toothpick to check for doneness in the center. Remember that ovens cook differently, so your baking time could vary.
• Allow to cool for about 10 minutes before removing from the sides of the springform pan. Continue to cool on a baking rack, and dust with powdered sugar when ready to serve. The cake can be served warm or at room temperature, with or without the cinnamon whipped cream.

to make cinnamon whipped cream

• Whip the cream, sugar, and cinnamon until soft peaks form. Keep refrigerated until needed.