1. Preheat oven to 180°C (350°F). Grease and flour a 23 cm (9-inch) round cake pan with removable bottom, or line with parchment for easier release.

2. In a large bowl, sift together flour, granulated sugar, baking powder, and salt. Whisk to blend evenly.

3. In a medium bowl, beat eggs lightly. Add milk, melted butter, and 1 tbsp vanilla extract. Whisk until smooth.

4. Pour wet ingredients into dry ingredients. Fold gently with a spatula until just combined—do not overmix.

5. Divide batter evenly into two large bowls. Add red food coloring to one portion. Stir until uniformly pink.

6. Pour the pink batter into the center of the prepared pan. Spread gently to cover the base.

7. Carefully pour the white batter directly on top, centering it so it spreads evenly over the pink layer without stirring.

8. Rotate the pan slightly in a swirling motion with your wrist to create a soft marbled effect—do not overwork.

9. Bake 35 to 40 minutes, or until golden and a toothpick inserted near the center comes out clean.

10. Let cake cool in pan for 10 minutes. Run a knife around the edge, then remove outer ring and cool completely on a wire rack.

11. While cake cools, prepare topping: in a chilled bowl, whip cold cream with powdered sugar and 1 tsp vanilla until soft peaks form—do not overwhip.

12. Once cake is fully cooled, spread cream evenly over the top, leaving a slight border to highlight the swirl.

13. Artfully arrange raspberries and blueberries over the cream to resemble a carousel canopy—use larger berries at the center, smaller ones radiating outward.

14. Serve immediately, or chill up to 2 hours before serving to firm the cream. Slice with a sharp, warm knife for clean layers.