Prep the pan and oven: Heat oven to 325°F (163°C). Line the bottom of a 9-inch springform pan with parchment and lightly grease the sides.
Make the crust: Stir oat flour, almond flour, sweetener, and salt.
Add melted butter and 1 tablespoon water. Mix until it holds together when pressed. Add another splash of water if crumbly.
Press and pre-bake: Press crust evenly into the pan.
Bake 8–10 minutes until set and lightly golden. Cool for 5 minutes.
Beat the cream cheese: In a large bowl, beat cream cheese until smooth and fluffy, about 1–2 minutes. Scrape the bowl.
Add yogurt and flavor: Beat in Greek yogurt, vanilla, lemon juice, zest, and salt until smooth.
Sweeten and add protein: Mix in maple syrup (or preferred sweetener).
Whisk protein powder to remove lumps, then beat it into the batter on low until just combined. Avoid overmixing.
Add eggs: Beat in eggs one at a time on low speed. Stop when the batter is silky and uniform. Do not whip air into it.
Fill and smooth: Pour batter over the crust.
Tap the pan gently on the counter to release bubbles. Run a spatula over the top to level.
Bake: Bake 40–50 minutes. The edges should be set and the center slightly wobbly.
If the top is browning too fast, tent loosely with foil.
Cool gradually: Turn off the oven, crack the door, and let the cheesecake rest inside 30 minutes. Then cool on a rack until room temperature.
Chill: Cover and refrigerate at least 6 hours, preferably overnight, to fully set and develop flavor.
Cook the cherries: In a small saucepan, add cherries, sweetener, and lemon juice. Simmer over medium heat 5–8 minutes, stirring.
Stir in cornstarch slurry and cook 1–2 minutes until glossy and lightly thickened. Remove from heat and add almond extract if using. Cool completely.
Top and serve: Spoon cherry topping over the chilled cheesecake.
Slice with a knife warmed under hot water and wiped dry for clean edges.