Pour grapefruit juice into small saucepan then add gelatin. Soak 2–3 minutes.
Add Truvia or sugar and stir on low heat until gelatin and sweetener have dissolved completely–about 5 minutes.
Add vodka and water then transfer to baking pan. Refrigerate several hours or overnight.
Cut into rectangles and transfer to a serving tray. Garnish with grapefruit and raspberries. Cheers!
Notes
It helps to remove the shots from the pan with a stainless steel brownie spatula. Your 'shots' will maintain their shape when you transfer them to a serving tray.