prep: preheat oven to 325°f. line an 8×8-inch pan with parchment paper or line a muffin pan with parchment muffin cups.
make the crust: in a bowl, mix almond flour, oat flour, coconut sugar, melted butter or oil, milk, vanilla, and salt until evenly combined. press firmly into the bottom of the pan or muffin cups. do not pre-bake.
make the cheesecake filling: in a mixing bowl, lightly mix all ingredients until a thick custard-like texture forms. try to not overmix. pour the filling evenly over the unbaked crust.
bake: in an 8×8 pan: bake 43-47 minutes. for cheesecake bites: bake 23–26 minutes. the edges should be set and the center should have a gentle jiggle.
cool + chill: let cool completely at room temperature. refrigerate for at least 4 hours (6 is best) until fully set. you can also place in the freezer for an hour to speed up the process.
make the whipped topping: in a bowl, whisk or beat the peanut butter, greek yogurt, maple syrup, and vanilla until light, smooth, and fluffy. spread or dollop the topping over the chilled cheesecake just before serving.