To make Frangipane: Beat, at medium speed, sugar, Marzipan and 1 egg until combined. Add butter, vanilla, and lemon zest and beat until reasonably smooth. Beat in the second egg.
In a separate small bowl, sift flour, baking powder and salt. Add to the butter mixture just until incorporated. Cover and chill 2 hours or overnight.
Tart Shell: In a large bowl, combine flour and sugar. Make a well in the center, drop in butter cubes and egg yolk. With your finger tips, crumble everything together to achieve an appearance of ‘coarse meal’. It should be crumbly, but holds together when squeezed in a handful. If it doesn't, work in 1/4 tsp of water.
Sprinkle and press dough into an 11" x 4" tart pan (or 9” round tart pan), starting with the sides. (Goal is to make a flat top, with good right angles where the bottom meets the sides) then flatten the bottom. TAKE YOUR TIME! Chill for 30 minutes.
When Frangipane is ready, fill the shell and smooth with an off-set spatula. Top with fruit, leaving room between pieces. No need to ‘press’ the fruit in as the Frangipane will wrap around pieces nicely as it bakes. Set rack for top third of oven.
Bake at 350 degrees (convection oven) for 35 minutes, until shell and top are nicely browned.