Prepare the base. In a medium bowl, mix the crushed graham crackers or vanilla wafer cookies with the melted butter. Add the optional powdered sweetener and cinnamon. Stir until the mixture looks like damp sand. If the crumbs do not hold together when pressed, add unsweetened almond milk one teaspoon at a time. Divide the crumb mixture evenly among eight clear dessert cups. Press lightly into the bottom to create an even base. Do not pack too firmly, or the base will become hard. Refrigerate the cups while you make the filling.

Blend the peanut butter filling. Add the Greek yogurt and cottage cheese to a blender. Blend until completely smooth with no visible lumps. This step is crucial for a creamy texture. Add the peanut butter, softened cream cheese, powdered sweetener, instant pudding mix, vanilla extract, optional powdered peanut butter, and sea salt. Blend again until creamy and evenly combined.

Adjust the consistency. If the peanut butter filling feels too stiff to spoon easily, slowly add almond milk or regular milk. You want a thick but pipeable consistency. Gently fold in the light whipped topping if you are using it. Be careful not to overmix, as this can deflate the whipped topping.

Make the chocolate swirl. In a separate bowl, combine the Greek yogurt, softened cream cheese, cocoa powder, powdered sweetener, chocolate pudding mix, vanilla extract, and optional peanut butter. Use an electric mixer or blend until smooth. Add almond milk gradually if the mixture is too thick. Gently fold in the optional whipped topping. Keep this mixture thick enough to form visible ribbons when swirled.

Layer the cups. Remove the cups from the refrigerator. Spoon or pipe the peanut butter cheesecake filling into the eight prepared cups. Follow with portions of the chocolate cheesecake mixture. Alternate the fillings to create layers and ribbons. Use a skewer or a thin knife to make a few gentle strokes through the mixtures. This creates the marbled effect. Avoid overmixing so the colors remain distinct.

Prepare the mousse topping. Blend the Greek yogurt, softened cream cheese, powdered sweetener, and vanilla extract until smooth. Gently fold in the light whipped topping. Add the cocoa powder and optional peanut butter, mixing gently to create a light, creamy marbled mousse. You want a swirled look on top, not a fully blended brown color.

Top the cups. Divide the mousse topping among the eight cups. Spoon it gently over the cheesecake layers or pipe it on using a piping bag fitted with a large tip. Spread evenly or leave small peaks for a rustic look. Refrigerate the cups while you make the chocolate drizzle.

Make the chocolate drizzle. Combine the chocolate chips with the warm milk or light cream in a small bowl. Stir until the chocolate is fully melted and smooth. Add the optional coconut oil for extra shine. Allow the drizzle to cool slightly. It should be fluid but not hot, otherwise it will melt the mousse underneath.

Decorate and chill. Drizzle thin lines of chocolate over the mousse topping. Use a small spoon or a fork for a delicate pattern. Add your choice of optional toppings, such as chopped peanuts, mini chocolate chips, chocolate shavings, crushed cookies, miniature peanut butter cups, or flaky sea salt. Cover the cups and refrigerate for at least 2 hours. Overnight chilling yields the firmest, most cheesecake-like layers. Serve cold.