Whisk the flour, baking powder and salt together and set aside.

Cream (beat) the sugar and butter until light and fluffy. Pour the egg and continue to mix to form a homogenous mixture. Spoon in the flour mixture and mix only to combine the ingredients. Dump the mixture onto a cold work surface and lightly knead with heal of your palm for 2 minutes. Be careful to not overwork the dough (good dough is crumbly and cold). Collect the dough and tightly wrap in plastic. Refrigerate for at least 30 minutes.

Meanwhile, dice 1-1/2 apples and thinly slice the remaining apples. Place the diced apples, sugar, vanilla, lemon juice and water in a saucepan. Cover the pan and place over low heat and cook for 15-20 minutes, stirring occasionally. The filling is cooked once the apples are translucent and water evaporates. Pour the filling in a tray and let it cool completely.

Preheat the oven to 175°C / 350°F and refrigerate an 8-inch tart pan until use. Remove the dough from the refrigerator and leave at room temperature for 5 minutes. Place the chilled pastry dough on a lightly floured work surface and fold it 2-3 times to make it pliable. Dust some flour on a rolling pin and begin rolling the dough from the center to the edge. Turn the dough 90-degrees after each rolling action. Continue to roll and turn, till the dough is an even disc with 10-11”diameter. Brush off any excess flour from the dough and roll the dough onto the rolling pin. Hold the rolling pin on top of the pan and unroll the dough leaving 2-inches outside the pan. Gently, push (not press) the dough into the corners. After the dough properly covers the inside of the pan, trim the excess dough and chill the shell for 10 minutes.

Fill the shell 3/4 full with apple filling. Arrange the apple slices around the tart shell, starting from the outside, overlapping the core.

Bake the tart for 1 hour, or until the crust is brown and the top apple slices are tender.

Prepare the glaze by boiling half-cup water and apricot jam. Once the solution boils, strain to remove apricot chunks and return the glaze to simmer.

Unmold the tart and brush the top with a thin layer of glaze. Slice using a serrated knife and serve warm.