Prepare the clear layer: In a large bowl, whisk the sugar-free gelatin with 2 cups boiling water until completely dissolved, about 1–2 minutes.

Add 1 cup cold water to the gelatin and stir. Pour half of the mixture (about 1.5 cups) into a 9x9-inch dish or 8–10 individual cups. Chill for 30–45 minutes, or until softly set.

Make the creamy layer: In a separate bowl, whisk together the heavy cream, Greek yogurt, and vanilla until smooth. If you like it sweeter, add powdered sweetener to taste.

Combine for the creamy jello: Stir the remaining half of the liquid gelatin (still at room temp) into the cream-yogurt mixture. Whisk until fully blended.

Layer it up: Gently pour the creamy mixture over the partially set clear layer. Tilt the dish to distribute evenly.

Chill: Refrigerate for 2–4 hours, or until fully set. For neat slices, aim for at least 4 hours or overnight.

Serve: Cut into squares or scoop into bowls. Top with a few berries or a small swirl of whipped cream if you like.