Step 1

Lightly coat the inside of a Bundt pan or mold with the cooking spray. Combine the cranberries, juice, sugar, zest, rosemary and a pinch of salt in a saucepan over medium-high heat. Bring to a boil, then reduce to a simmer and cook, stirring occasionally, until the cranberries have burst and the sauce has thickened, about 20 minutes. Cool slightly.

Step 2

Meanwhile, in a small bowl, sprinkle the gelatin over 1/4 cup water and let stand until the gelatin blooms, about 5 minutes. Once the cranberry mixture has cooled, discard the rosemary sprigs.

Step 3

Using an immersion blender, blend the cranberry mixture until it is smooth but still has consistency, about 30 seconds. Add the gelatin mixture and the vanilla and blend 5 more seconds. Pour the mixture into the prepared pan, then cover loosely with plastic wrap and refrigerate for at least 8 hours or up to overnight.

Step 4

To unmold, carefully run a butter knife or small spatula around the edges and around the center of the pan and turn out onto a serving platter. (If needed, run hot water under the pan to help loosen the cranberry.)