Step 1: Prepare the Cake Batter

1. Preheat your oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
2. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
3. In a large mixing bowl, cream the butter and sugar together using an electric mixer on medium speed until light and fluffy, about 2–3 minutes.
4. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
5. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk. Begin and end with the dry ingredients. Mix just until combined.
6. Pour the batter into the prepared pan and smooth the top with a spatula.

Step 2: Bake the Cake

1. Bake for 30–35 minutes or until a toothpick inserted into the center comes out clean.
2. Remove the cake from the oven and allow it to cool for 10 minutes in the pan.

Step 3: Make the Cranberry Filling

1. While the cake bakes, combine the cranberries, sugar, water, and orange zest in a medium saucepan.
2. Cook over medium heat, stirring occasionally, until the cranberries burst and the mixture thickens, about 10–12 minutes.
3. Remove from heat and let the filling cool slightly.

Step 4: Poke the Cake

1. Once the cake has cooled slightly, use the handle of a wooden spoon to poke holes evenly across the surface of the cake, about 1 inch apart.
2. Pour the cranberry filling over the cake, spreading it with a spatula to ensure it seeps into the holes.

Step 5: Prepare the Whipped Cream Frosting

1. In a chilled mixing bowl, beat the heavy cream, powdered sugar, and vanilla extract on high speed until stiff peaks form.
2. Spread the whipped cream frosting evenly over the cooled cake.

Step 6: Decorate and Chill

1. Garnish the cake with sugared cranberries, rosemary sprigs, and a sprinkle of edible glitter for a festive touch.
2. Chill the cake in the refrigerator for at least 1 hour before serving.