Preheat the Retigo combi oven to 160C. Grease an enameled GN container with butter and line the base with baking paper. Measure all the ingredients into a large bowl and beat for 2 minutes, or until well blended. Turn the mixture into the prepared tin and level the top. Bake for 25 minutes, until the cake has shrunk a little from the sides and springs back when lightly touched with a fingertip in the centre of the cake. Meanwhile, make the glaze. Mix the sugar with the lemon juice and stir to a runny consistency. Leave the cake to cool for 5 minutes in the GN container, then lift out, with the lining paper still attached, and place on wire rack set over a tray. Brush the glaze all over the surface of the warm cake and leave to set. Remove the lining paper and cut into slices to serve.