1 For the cake: Preheat the oven to 190°C (170° fan) 375°F gas 5. Grease a deep 20 cm | 8" cake tin and line the base with non-stick baking paper.
2 Beat the butter and sugar in a mixing bowl until light and fluffy.
3 Add the eggs, one at a time, beating well to combine, then beat in the vanilla. Sift in the flour and and mix gently until blended.
4 Spoon into the tin and bake for 50-60 minutes until golden and springy to the touch. Cool in the tin for 5 minutes, then place on a wire rack to cool completely.
5 Cut the cake horizontally in two. Place one half upside down.
6 For the filling: stir the jam to loosen and spread over the inverted cake half. Place the remaining cake on top and sift icing sugar over the top.