Method

To make the pastry shells:

1. Preheat the oven to 350°F / 180°C.
2. Place 1 sheet of filo pastry on a flat dry surface and brush with some melted butter. Place another sheet of filo pastry on top of the first sheet and brush with more melted butter. Repeat this process until 6 sheets of the filo are stacked on top of each other.
3. Cut the stack of filo sheets into two 7in / 18cm squares; discard the trimmings.
4. Gently press each stack of filo into a shallow 4 ½ in / 10-11cm diameter loose based tartlet pan.
5. Using kitchen shears, trim away the excess pastry, leaving about 1/2 inch of pastry above the rims of the tart pans.
6. Place the tart pans on a heavy baking tray.
7. Repeat with the remaining 6 filo sheets and melted butter.
8. Bake the pastry shells for 15 to 20 minutes or until dark golden brown.
9. Carefully lift the shells from the pans and place them on a rack to cool completely.

To make the filling:

1. Bring a large saucepan of water to a boil over medium-high heat.
2. Reduce the heat to low.
3. Whisk the eggs, sugar, lemon juice, and zest in a medium stainless steel or glass bowl to blend.
4. Place the bowl over the hot water and whisk in the butter.
5. Continue to whisk for about 3 minutes or until the curd has become thick and creamy and coats the back of a spoon.
6. Remove from the heat and whisk until most of the heat has dissipated from the lemon curd, about 10 minutes.
7. Set the lemon curd aside to cool completely, stirring occasionally. The curd will continue to thicken as it cools.
8. Spoon ½ cup of the lemon curd into each tart and top with the raspberries.
9. Dust with powdered sugar, and serve.