Preheat oven to 375 degrees Fahrenheit.
Place the flour, sugar, baking powder and salt into a food processor and pulse about 5 times until combined.
Cut the butter into 6 pieces and add to the flour. Pulse 10-15 times until the butter is incorporated and the mixture looks powdery or sandy.
Add the egg and egg yolks and pulse until the dough comes together.
Dump the dough out onto a lightly floured surface and knead 5-6 times to form a smooth dough. Divide the dough into 2 pieces, 2/3 and 1/3. Wrap dough in plastic wrap and place in refrigerator for at least 1 hour.
After chilling, roll the 2/3 piece into a circle 1/8” thick and use it to line the bottom and sides of the tart pan.
Roll the remaining dough between 2 sheets of parchment paper in the shape of a rectangle 1/8” thick. Place on a sheet pan and put in the freezer for 10 minutes to firm up the dough.
Remove the sheet of dough from the freezer and cut into 1” wide strips. Place 5 strips over the jam spaced evenly apart. The strips should hang over the edge of the pan. Cut off any excess dough even with the edge of the pan and press lightly to adhere to the crust edge. Cut 5 more strips and place them across the existing 5 creating a lattice pattern. Press lightly to adhere to the crust edge.
Brush the top crust with the beaten egg and sprinkle with the sliced almond.
Bake for 30-35 minutes or until golden brown.
Once out of the oven, immediately place the pan on a small bowl and let the pan rim slide off. I’ve found that if I let it cool even slightly any jam that has bubbled up over the edge will set up and it will be very difficult to remove the rim.
Place the tart with the removable bottom on a rack to cool completely.