Preheat the oven to 350°F. Line the bottom of a 9-inch cake pan with parchment paper.

Beat the eggs on high speed for about 1 minute, then gradually add sugar and continue beating until the mixture is thick and fluffy, approximately 10 minutes.

In a separate bowl, whisk together flour and baking powder, then sift this into the egg mixture. Gently fold with a spatula until combined.

Pour into the prepared pan and bake for 23 to 25 minutes until golden. Cool for 5 minutes in the pan, then loosen edges, transfer to a wire rack, and peel off parchment.

Wash and hull strawberries, halving them.

Heat half of the cranberry juice until it just simmers, then remove from heat and stir in sugar if using.

Sprinkle gelatin over the remaining cold juice and let it sit for 2 minutes, stirring occasionally.

Combine warm juice with gelatin mixture and pour into the trifle bowl. Refrigerate until semi-firm, about 2 to 3 hours.

Distribute strawberries around the sides and center of the jelly. Chill until fully firm, at least 3 hours or overnight.

Whisk egg yolks, 1/3 cup milk, sugar, and cornstarch in a large bowl.

Heat remaining milk over medium heat until simmering, gradually whisk into yolk mixture, then return to the pan.

Cook over medium heat, whisking constantly, until thickened and able to mound on a spoon (about 5 to 7 minutes).

Remove from heat, strain through a fine sieve into a bowl, and stir in chopped white chocolate until melted.

Cover with plastic wrap directly on the surface and refrigerate until cold, at least 4 hours or overnight.

Before assembling, fold mascarpone cheese and orange liquor until combined.

In another bowl, beat heavy cream, powdered sugar, and vanilla until fluffy with soft peaks.

Fold half the whipped cream into the mascarpone to lighten, then fold in the rest until smooth.

Pour chilled white chocolate custard over the jelly layer.

Crumble the sponge cake over the custard, then sprinkle with a mixture of strawberries, raspberries, and blueberries.

Spread the mascarpone cream evenly on top.

Decorate with extra berries, fresh mint leaves, and a dusting of powdered sugar for a festive finish.