Preheat oven: 180°C / 160°C (fan) / Gas Mark 4 / 350°F
In a mixing bowl, stir together the treacle, syrup, zest and lemon juice until smooth, then pour this into the base of a greased 8-inch square baking tin.
In a separate bowl, cream together the butter and sugar until smooth.
Beat in the eggs, one at a time, until fully combined.
Sieve in the flour and baking powder, gently folding this until the mixture until just combined.
Stir in the milk until smooth and then spoon the batter over the syrup in the pan and smooth gently until evenly spread across the syrup layer.
Cover the tin with a layer of foil and bake for 40-45mins until the sponge is risen and a skewer comes out clean from the middle. Cut your sponge pudding into pieces and serve each slice upsidedown.
