First, make the pie crust. Add the flour, sugar, salt, and baking powder to a large bowl. Whisk together. Add in the shredded butter and stir until the pieces of butter are broken up into the flour.
Add in the whisked eggs and vanilla extract. Using your hands, start mixing the dough in the bowl. When it starts to come together transfer the dough onto a work surface. Knead until a dough ball has formed. Break into two pieces and form each into a disk. Wrap in plastic wrap and refrigerate for at least 30 minutes.
While the dough is refrigerating prepare the filling. Add all of the ingredients (except for one egg) into a large bowl and using a hand mixer or whisk, mix until fully combined. Set aside.
Preheat the oven to 350℉.
Remove the two discs from the refrigerator and dust a work surface with flour. Roll out each disc into 9-inch circles.
Fit one pie crust into a 9-inch pie pan. Slice the second crust into 12 long pieces. Set aside.
Transfer the filling into the pie crust. To make the lattice top, lay 6 strips of crust on a piece of parchment paper and weave the remaining 6 pieces in. Flip the crust onto the top of the pie. Whisk the remaining egg and use a pastry brush to brush the top of the crust.
Bake for 50-60 minutes. Similar to a cheesecake, this pie should have a little giggle to it in the middle. If it is still loose on the outside then bake for an additional 10 minutes.
Cool for 30 minutes then refrigerate for at least 4 hours or overnight.
Serve with powdered sugar and fresh berries.