Instructions

1. Wash and slice the rhubarb stalks (slice them thinly if you want them to stay on top of the cake). Place the rhubarb slices on a plate, squeeze lemon juice over and gently toss to cover all the slices with juice. Set aside while you prepare the cake batter.
2. Preheat the oven to 175°C (350°F). Grease a 20 x 20cm (8 x 8 inches) square baking pan or a 23 cm (9 inch) springform pan. Cover the pan with baking paper for easy removal of the cake, or if using a springform pan, dust with flour.
3. In a saucepan, melt the butter and add the milk. Set aside to cool completely.
4. Sift the flour, baking powder and salt into a medium bowl. Set aside.
5. In a large bowl, beat the sugar and eggs until light and fluffy, about 2 minutes. Stir in the grated almond paste.
6. Pour the cooled butter mixture into the egg mixture and stir until combined. Add the dry ingredients and lemon zest and stir until the batter is smooth.
7. Pour the batter into the prepared pan and place the rhubarb on top, in a pattern if you wish. Sprinkle with 1 tsp. sugar. Bake the cake on the lowest rack for 45-50 minutes. Cover the cake with aluminum foil if the rhubarb is browning too much.
8. Leave the cake to cool, then dust with powdered sugar and serve with whipped cream or ice cream.