Begin by sifting the flour and baking powder into a large roomy bowl, lifting the sieve high to give the flour an airing.
Now just add all the other ingredients and, using an electric hand whisk, whisk for about one minute until you have a smooth creamy mixture that drops off a spoon easily. Next, spoon the mixture into the tin, levelling it with the back of the spoon, and bake near the centre of the oven for 30–35 minutes or until the centre feels springy.
Leave the cake in the tin for 5 minutes before loosening the edge with a palette knife and turning it out onto a cooling rack. Now peel off the liner, turn the cake upright and let it get quite cold.
To serve the cake, first whisk the cream in a large bowl until stiff. Next you need to place the cake on a flat surface and using a serrated knife carefully split it horizontally into two thin halves. Now, leaving the two halves stacked one on top of the other, divide the cake into quarters, then each quarter into two (so you have 8 wedges of sponge cake).
Remove the top layer of wedges and arrange the bottom layer on a serving dish, re-forming it into a round. Weigh out 200g of the hulled strawberries, and whizz them to a purée with one dessertspoon of caster sugar. Now, spread half the cream over the cake and top with the remaining hulled strawberries (slicing any large ones in half and making sure the berries round the edges are showing).
Spoon over the purée and cover with the other half of the cream, then re-form the top layer, making sure it lines up with the base. Dust the whole thing with icing sugar, then cut the reserved strawberries in quarters through the stalk and use to decorate the top of the cake.
See Delia's Classic Sponge Cake (used in this recipe), and other sponge cakes being made in our Cookery School Video.
Pre-heat the oven to 170°C, gas mark 3
Using a fan-assisted oven? Click here
You will also need a Delia Online 20cm x 4cm Round Loose-based Sponge Tin, or similar, lightly greased and base lined, plus a cooling rack
The Delia Online Bakeware range is now available online, and you can buy our 20cm Round Sponge Tin with loose-base, and washable, reusable liners direct from Silverwood