1. Preheat the oven to 225°F and line a baking sheet with parchment paper.

2. Add the egg whites to a clean mixing bowl and beat until foamy.

3. Add the cream of tartar and continue beating until soft peaks form.

4. Slowly add the granulated sugar, one tablespoon at a time, beating until the meringue is glossy and stiff peaks form.

5. Mix in the vanilla extract and green gel food coloring until evenly combined.

6. Transfer the meringue to a piping bag fitted with a large star tip and pipe wreath shapes onto the prepared baking sheet.

7. Bake for 1 hour, then turn the oven off and leave the meringues inside for 1 additional hour without opening the door.

8. Remove the meringues and let them cool completely.

9. Beat the heavy whipping cream with the powdered sugar until medium peaks form.

10. Pipe or spoon the whipped cream onto the cooled wreaths.

11. Top with fresh cranberries or red currants and garnish with rosemary sprigs.

12. Dust lightly with powdered sugar just before serving.