Zest grapefruit and set aside. Juice and strain ½ cup grapefruit juice and set aside.

Stir together powdered gelatin and water and allow to bloom.

Combine cream, powdered sugar and zest and bring to a boil.

While the liquid is hot, add gelatin mixture and stir until dissolved.

Strain liquid over grapefruit juice and stir to combine.

Distribute panna cotta into 4 small bowls (5- to 6-ounce bowls are ideal; 3½ ounces per portion).

Cover and refrigerate until gelatin sets.

Stir together powdered gelatin and 4 teaspoons water and allow to bloom.

Combine grapefruit juice, ⅛ cup water and sugar and bring to a boil.

While the liquid is hot, add gelatin mixture and stir until dissolved.

Allow gelee to cool to room temperature.

Distribute gelee evenly on top of each bowl of panna cotta. (Pour carefully to avoid puncturing the panna cotta.)

Cover and refrigerate until gelatin sets.