Preheat oven to 180°C and line a 27.5 x 17.5cm (base) brownie pan with baking paper.

Place butter and vanilla in a bowl. Use an electric mixer to beat until creamy. Add sugar and eggs and continue to beat until light and fluffy. Add half of the flour along with half of the milk, beat to combine, then repeat with remaining flour and milk. Pour batter into prepared pan and bake in preheated oven for 30-45 minutes, or until cake springs back when lightly touched. Cool in pan for 10 minutes before transferring to a wire rack. Poke holes halfway into the cake using the end of a wooden spoon.

Combine jelly crystals and boiling water in a jug. Whisk until crystals are completely dissolved, then pour over the top of cake. Refrigerate for at least 2 hours.

Combine cream and icing sugar in a bowl and beat with an electric mixer until soft peaks form. Spread over cake, then return to the refrigerator until needed. Serve sliced into squares with fresh strawberries (if desired).