Prepare Your Ramekins: Start by lightly coating six 6-ounce ramekins with cooking spray. Then, use a paper towel to wipe away most of the oil, leaving just a faint layer. This helps the panna cotta release easily after setting.
Soften the Gelatin: Pour the whole milk into a medium saucepan. Sprinkle the gelatin powder evenly across the surface of the milk and let it rest undisturbed for about 5 minutes. You'll notice the milk surface wrinkle slightly as the gelatin absorbs moisture and begins to soften.
Gently Warm to Dissolve Gelatin: Place the saucepan over low heat. Slowly warm the milk and gelatin mixture, stirring gently but continuously with a whisk or spoon. The goal is to heat the liquid just enough for the gelatin to melt completely—avoid any boiling or simmering. The mixture should feel warm to the touch but comfortable enough to hold your finger in briefly.
Confirm Gelatin Is Fully Melted: After 2–3 minutes of warming, test a small amount by rubbing it between your fingers or checking the back of a spoon. The liquid should feel smooth without any gritty gelatin granules. If you detect undissolved bits, continue warming briefly.
Sweeten the Mixture: Add the granulated sugar to the warm milk and gelatin, stirring until fully dissolved. This process usually takes just a few minutes. Again, keep the heat low to prevent boiling, which would impair the gelatin’s setting ability.
Incorporate Cream and Flavor: Remove the saucepan from heat. Whisk in the cream, vanilla extract, and a pinch of salt until everything is evenly combined, creating a luscious, smooth mixture.
Pour and Chill: Divide the panna cotta mixture evenly into the prepared ramekins. Place them in the refrigerator to chill and set. For a softly set dessert served directly in the ramekins, chill for 1 to 2 hours. For panna cotta that can be unmolded onto plates, allow at least 4 hours, preferably overnight.
Prepare for Unmolding: When ready to serve, fill a large bowl with warm (not hot) water. Lightly moisten a serving plate with a damp paper towel to help with repositioning the panna cotta once unmolded.
Release Edges and Unmold: Run a thin knife carefully around the inside edge of each ramekin to loosen the panna cotta. Avoid inserting the knife too deeply to keep the dessert intact. Dip the ramekin rim into the warm water for about 3 seconds to gently warm the sides. Immediately invert the ramekin onto the prepared plate, gently shaking or pressing to release the panna cotta.
Serve or Store: Serve the panna cotta immediately or cover and refrigerate for up to five days. Note that the gelatin firms more over time, potentially becoming firmer or slightly rubbery. To soften before serving, let it rest at room temperature for about 30 minutes.