Heat the oven to 350 F. Stir the rolled oats, almond flour, melted butter, maple syrup, cinnamon, and salt together on a parchment-lined baking sheet.
Bake the crumble for 12 to 15 minutes, stirring once, until golden and crisp. Let it cool completely.
Cook the diced apples, butter, maple syrup, lemon juice, and cinnamon over medium heat for 7 to 9 minutes, until the apples are tender but still hold their shape.
Stir the cornstarch and water together, then add the mixture to the apples. Cook for 1 minute, until the juices become glossy and thick, then cool the filling.
Blend the cottage cheese, Greek yogurt, maple syrup, and vanilla extract until completely smooth and creamy.
Layer the cottage cheese cream, cooled apple filling, and oat crumble in six dessert glasses.
Refrigerate the parfaits for 30 minutes, then add a final spoonful of crumble immediately before serving.