Step 1 Preheat oven to 180°C. Grease and line a 24cm square cake pan with baking paper. Add spread and sugar to a mixing bowl and beat until light and fluffy.
Step 2 Beat in eggs, then fold in almond meal, mashed potato, lemon zest and baking powder.
Step 3 Spoon mixture into prepared pan and bake for 40-45 minutes or until firm to the touch and lightly golden. Cool in pan for 5 minutes before removing. Set aside to cool completely.
Step 4 To make lemon drizzle, place sugar and lemon juice in a small saucepan over low heat. Cook, stirring, until sugar dissolves. Continue cooking, stirring, for a further 3 minutes or until mixture is slightly thickened.
Step 5 Use a skewer to prick top of cake. Drizzle over syrup. Set aside for 1 hour, then cut into even pieces. Sprinkle with icing sugar, top with extra zest and serve.