Preheat oven to 400F.
Add flour, sugar, and salt to the bowl of a stand mixer fitted with the beater attachment. Stir together on lowest speed until combined.
Increase speed to medium and add butter, beating until butter is no larger than pea-shaped pieces.
In a small bowl, lightly whisk egg yolk, water and vanilla until just combined. Add to dry ingredients and beat on medium speed until dough comes together.
Turn out dough onto a lightly floured workspace. Form into a disk. Then, roll out dough evenly, flipping and rotating every so often so the dough doesn't stick to workspace (add more flour if needed). Roll into a circle, about 1/8-inch thick.
Transfer dough to a tart pan that is 10-inches in diameter and has a removable bottom. Press along bottom and sides, using your fingers to trim off any excess dough. Spray a piece of aluminum foil with cooking spray and place on top of dough. Top with pie weights. Place filled tart pan on top of a cookie sheet, for baking.
Bake in the preheated oven for 15 minutes. Remove pie weights and foil and return to oven, baking for another 3 minutes, until just starting to brown. Remove from oven and set on a wire rack to cool.
In a stand mixer fitted with the paddle attachment, beat butter and sugar on medium speed until light and fluffy, about 3 minutes. With the mixer still running, add eggs, one at a time, until incorporated. Scrape down sides of the bowl and add almond extract.
Reduce speed to low and add sea salt, baking powder, almond flour and all-purpose flour, a little at a time. Mix until just incorporated. Scrape down sides of the bowl and give one more mix, with a rubber spatula, if needed.
With a thin spatula or butter knife, spread jam along the bottom of the crust, covering the bottom as best as possible.
Top jam with tart filling, doing your best to spread evenly across the top. It's ok if a little jam peeks out - it'll settle in baking.
Top with slivered almonds.
Bake in preheated oven for about 40 minutes, checking partway through. If the top is browning too quickly, cover edges with aluminum foil. The tart is done when the top is firm and is puffed up all the way to the center. Remove from oven and transfer to a wire rack to cool completely before serving.