Combine 1 1/4 cups champagne, lemon juice and sugar in a saucepan. Sprinkle gelatin on top. Let gelatin soften for about two minutes to bloom, then heat mixture over low heat. Stir until gelatin has completely dissolved, about 2-3 minutes, and remove from heat. Stir in remaining 1/4 cup each of champagne and vodka.
Grease a loaf pan with nonstick cooking spray. Pour mixture into mold and chill for 2 hours, or until firm.
Invert jello to parchment paper-lined cutting board and slice into squares. Dip each square in sprinkles and serve cold.