Cut cake into 2 cm / 0.8" cubes. Cover bottom of 3.5 L / 3.5 qt trifle dish with cake (might not use all) and sprinkle with liquor or juice.

Optional extra: Scatter over 1/2 to 1 punnet halved strawberries (this is not in ingredients list).

Heat half juice - Put half the cranberry juice into a saucepan over medium heat (3 cups / 750ml). Bring to a simmer, then turn off stove.

Dissolve geatline - Meanwhile, put remaining room temperature cranberry juice into a very large bowl. Sprinkle gelatine all across surface (don't dump in one place, else you get lumps). Whisk until mostly dissolved (will finish dissolving in next step).

Pour in hot cranberry juice. Whisk until gelatin is fully dissolved.

Pour HALF the warm jelly liquid carefully down the side of the trifle dish so the cake pieces are submerged. Refrigerate the trifle dish uncovered for 1 1/2 hours until it is partly set. It needs to be set enough so you can gently place a strawberry on it and it will stay on the surface. Proceed to Custard Layer steps.

Pour remaining warm jelly in a bowl and leave on the counter. DO NOT refrigerate.

Meanwhile, make the custard so it is ready to use (see below for how to make).

Remove trifle from fridge. Whisk the room temperature custard to loosen. Spoon onto the jelly, smooth surface, press against wall of glass to seal (stops jelly bleed so you get neat layers). Refrigerate uncovered for 1 hour until the surface has firmed up a bit - just enough to hold the jelly (jelly is soft, so custard doesn't need to be fully set).

Give the remaining jelly a good whisk then put it in the fridge at the same time to thicken a bit but not fully set. Refrigerate for 1 hour, but check at 30 minutes to ensure it isn't setting too fast. The jelly should be sloppy but spoonable, scoops up in a small mound. If it fully sets, you'll end up with a "broken glass" effect on the next jelly layer rather than a clear layer (read Note 5).

Remove trifle and jelly from fridge. Jelly should be sloppy. Carefully spoon over jelly, smooth surface. Scatter over 1 punnet halved strawberries (or half each raspberries and strawberries). Refrigerate for 3 hours+ (can leave in fridge for 48 hours, until ready to assemble).

Cream: Beat cream, sugar and vanilla until softly whipped.

Once jelly is set, just before serving, top with cream, then pile over remaining berries. Dust with icing sugar.

Serve!! PS It is imperative to ensure every servings includes a bit of every layer in the trifle 😂

Bring milk, 1/4 cup sugar and vanilla to a simmer in a large saucepan over medium heat. Do not boil.

In a large bowl, whisk together remaining 1/4 cup sugar and yolks, then whisk in cornflour until smooth.

While whisking, carefully pour in about 1/2 cup of milk mixture. Once mixed in, slowly pour in remaining milk while whisking. Once incorporated and smooth, pour back into saucepan.

Return saucepan to stove over low heat. Whisk constantly until it becomes thick and custardy – this will happen quite quickly, about 45 seconds (ie it is liquidy when you start, then suddenly it thickens). Once thickened, remove immediately from heat (it will continue to thicken as it cools).

Immediately pour into a bowl and cover with cling wrap, pressing onto surface. Leave on the counter to cool to room temp until trifle is ready to layer with custard. Makes 750ml. (Note 5)