Easy Lemon Bars

Step 1: Preheat the oven to 180°C/350°F (160°C fan). Spray a 20 cm / 8-inch square pan with oil, then line it with baking paper, leaving an overhang so you can lift the bars out after baking.

Step 2: For the base, put the shortbread base ingredients in a food processor fitted with the standard S blade. Pulse 5 to 10 times, until the mixture looks like sand. Alternatively, rub the butter into the dry ingredients with your fingertips. Pour the mixture into the pan, spread it out, and press it firmly into the base and right up to the edges. Use something with a flat base to help press it in.

Step 3: Bake the base for 20 minutes, or until the edges are golden and the middle is pale golden. Remove it from the oven and pour in the curd immediately; do not let the base cool.

Step 4: While the base bakes, put the lemon topping ingredients in a bowl and whisk until combined.

Step 5: Pour the lemon curd onto the base and bake for 20 minutes, until the topping is set but still soft.

Step 6: Remove the pan from the oven. Cool on the counter for 1 hour, then refrigerate for at least 2 hours. Slice into 16 squares. Dust with icing sugar, if desired, and serve.