Set up your cups: Place your serving cups on a tray that will fit in your fridge. This makes it easy to move them once filled.

Make the lemon base: In a large bowl, whisk the lemon Jell-O with the boiling water until completely dissolved, about 2 minutes. No grainy bits should remain.

Cool it fast: Add the cold water and then stir in the ice cubes. Keep stirring until the mixture thickens slightly and the ice mostly melts. Remove any unmelted ice.

Create two textures: Pour about half of the liquid Jell-O into a separate bowl. To one bowl, whisk in the yogurt until smooth for a creamy lemon layer. To the other, fold in half of the whipped topping for a light, mousse-like layer. This gives you two different lemon textures.

Layer the cups: Spoon a layer of the creamy yogurt-lemon mixture into each cup (about 1–2 tablespoons). Chill for 10–15 minutes to help it set slightly.

Add fresh fruit (optional): Drop a few berries on top of the first layer. They’ll sit nicely if the layer has started to thicken.

Add the mousse layer: Spoon the whipped-topping lemon mixture on top of the fruit or creamy layer. Fill each cup about three-quarters full.

Chill to set: Refrigerate for at least 2–3 hours, or until fully set. Overnight is even better for clean layers and easy serving.

Top and garnish: Just before serving, add a small dollop of the remaining whipped topping, a sprinkle of crushed shortbread or graham crumbs, and a pinch of lemon zest. Add a couple of berries for color.

Serve cold: Keep them on a chilled tray if you’re outdoors. These taste best very cold.