Mix the custard powder and sugar together with ⅓ of the milk until smooth, then pour in the rest of the milk and the vanilla bean paste.

Heat gently, stirring constantly with a wooden spoon until the custard begins to thicken.

Turn the heat very low and continue to cook until the custard is very thick (keep on stirring).

If the custard turns lumpy use a small handheld whisk to beat it until it turns smooth and/ or push it through a fine-meshed sieve.

Transfer the custard to a bowl and lay food wrap directly on the surface of the custard to stop skin forming. Let cool then refrigerate for at least 6 hours (or overnight).

Chop the rhubarb into small pieces about 1cm in length (if your rhubarb is wide also cut in half if it looks too out of proportion to the 1cm length).

Put into a large saucepan with the sugar and lemon juice.

Cook gently for 12-15 minutes until the fruit is soft and the liquid is thick and jammy. Stir as necessary with a wooden spoon but try not to break the fruit up too much.

Set aside to cool.

Preheat the oven to 180C/ 350F. Grease two 8-inch circular sandwich tins with butter and line the base of each with baking parchment.

Use electric beaters to cream butter and sugar together until light and fluffy.

Beat in the eggs, one at a time.

Add vanilla extract and soured cream. Beat again.

Mix flour, custard powder and baking powder together then sieve into the cake batter. Fold in using a large metal spoon. Keep mixing until no streaks of flour remain, then stop mixing.

Divide the cake batter between the baking tins and cook for 23-27 minutes until risen, golden and a cocktail stick poked into the centre comes out clean.

Let the cakes rest in the tins for 2 minutes then turn out onto a wire rack, remove the parchment and let cool completely.

Take the chilled custard out of the fridge and beat using electric beaters until a smooth consistency is reached. It will look horribly thick initially (see the image in the step-by-step section above). Once beaten the custard will turn smooth again.

Pour in the cream and beat again until combined and the mixture holds its shape (don’t let it get so thick that it will be hard to spread).

Put one of the custard sponge cake layers on a plate. Top with just over half of the rhubarb compote then spread around half of the creamy custard filling over it.

Top with the second layer of cake and spread the remaining compote over the top (to within 1-2cm of the cake edge). Use the leftover custard cream to pipe rosettes around the edge of the cake then top each one with a small strawberry.