In a food processor add the sugar and lemon zest, blitz for a moment to incorporate the zest allowing it to perfume the sugar.
Add the flour and half of the cubed cold butter, pulse about 10 times, add the remaining butter and pulse until you get small lumps the size of peas like making regular pie crust.
Remove the flour and butter mixture to a large bowl and add the eggs, mix together until you have a cohesive ball of dough. If it’s not coming together drizzle a tablespoon of water at a time onto the dry parts and squeeze together.
Wrap the disk of dough in plastic wrap and chill for 30 minutes.
On a floured surface roll out the dough into a large rectangle big enough to hang over the edge of a 18x13" sheet tray by several inches. Fold the dough into a quarter so it’s easier to pick up and place on the tray, unfold and using a scrap of dough press the dough into the corners and edges of the tray. Trim the tray around the edges, ball up the reaming dough and chill the scraps and the lined tray.
In a large bowl beat together all of the ingredients for the filling and set aside.
Preheat the oven to 350F.
With an offset spatula spread the jam on the base of the tart.
Blob the ricotta mixture all over the tart and spread evenly, try not to mix the layer of jam and ricotta together.
Re-roll the dough scraps and cut into thin strips, use these strips to create an open lattice on top of the tart. Pinch the lattice pieces to the edge of the dough and trim away the excess.
Bake at 350F for 30-35 minutes until the tart is set, the center will still be a little soft and jiggly. Let cool completely, serve at room temperature or slightly chilled but not cold.