Meyer Lemon Semolina Square 柠檬方块塔

Adapted from The Essentials of Baking

Ingredients 

Semolina crust:

• 1/3 cup all-purpose flour
• 1/3 cup semolina flour
• 1/4 cup icing sugar
• pinch of salt
• 90g cold unsalted butter, cut into small pieces

Lemon curd:

• 80g cold unsalted butter cut into small pieces
• 1 teaspoon finely grated meyer lemon zest (from about 1 lemon)
• 3/4 cup strained meyer lemon juice (from about 5 lemons)
• 3/4 cup sugar 
• 3 eggs

** icing sugar, for dusting

Method:

1. for the crust: preheat oven to 180C. Line an 8″ square pan with parchment paper on the bottom and up the sides. 
2. Combine the flours, sugar and salt in the bowl of a food processor. Add the butter cubes and pulse until like bread crumbs. Pour the crumbs into the prepared pan and press the dough as evenly as possible into the bottom.
3. Bake the crust until it is golden all over, about 15-20 minutes.

Make the curd:

1. Set a mesh sieve over a heatproof bowl or large measuring cup and set aside. Place the diced butter and lemon zest in a small bowl and set aside.
2. In a medium, heavy-bottomed saucepan, whisk together the sugar and eggs to combine. Whisk in the lemon juice. Place the pot over medium-low heat, and cook, stirring constantly with a heatproof rubber spatula, until the mixture thickens slightly and reaches 160-170º on an instant-read thermometer, about 5-10 mins. 
3. Immediately strain the mixture through the sieve to stop the cooking. Whisk in the butter pieces and zest until combined.
4. Pour the cooked curd over the baked crust and bake for about 20 minutes or until the center of the curd wobbles like firm jelly when you give it a gentle shake. If it is wet or watery-looking means under-bake and if it is puffed or cracking in the centre means over baked.
5. Remove the square from the oven and let cool for about 20 minutes, then chill until firm, 2-3 hours. Grasp the parchment and lift out from the pan and onto a cutting board; peel away the parchment. Trim away the outer edges, then  cut into 16 small squares, wiping the knife clean between cuts. 
6. Dust the tops with a bit of icing sugar just before serving.