Prepare 8 (4-ounce) ramekins by lightly spraying nonstick spray into each and wiping gently with a paper towel to distribute the spray evenly along the sides and bottom.

Add the gelatin to the cold water in a medium bowl, and allow to bloom (soften) for 5 minutes; do not stir.

Meanwhile, stir the heavy whipping cream and sugar together in a small saucepan set over medium heat. Heat, stirring occasionally, until the sugar is fully dissolved at just barely a simmer.

Slowly add the warm sugar cream to the gelatin and stir until the gelatin is fully dissolved.

Pour the half-and-half into a large bowl (or a large pitcher for easier pouring) and, stirring continuously, slowly pour the warm cream mixture into the half-and-half.

Stir in the espresso.

Fill the ramekins equally and refrigerate uncovered for approximately 5 hours until chilled and completely set.

To unmold the panna cotta, dip the bottom of each ramekin into very hot water for 45 seconds, or until you can see the panna cotta just beginning to melt around the sides. You may also take a knife and run it around the inner circumference of each ramekin. Place a dessert plate on top of the ramekin, then holding both the ramekin and plate, simply invert.