In the bowl of a food processor fitted with the metal blade, combine first 4 ingredients and pulse to combine. Add cold butter and process just until pea-size pieces form. Start to pour the ice water through the feed tube and turn on the food processor. Blend until dough just comes together. Test this by squeezing a small handful of dough – it should clump together. If doesn’t, add a few more drops of water. Gather dough into a ball. Flatten into a disk. Wrap in parchment paper and chill at least 1 hour.
Preheat oven to 400 degrees. Place a sheet of foil on the lower rack of the oven to catch any drippings.
Gently combine all the filling ingredients (except crumbs and egg) in a medium bowl and set aside.
Dust the countertop and a rolling pin lightly with a little spelt flour and some cornmeal. Unwrap the disk of dough and place the parchment paper on a rimless baking sheet or you can use the underside of a rimmed baking sheet. This will make it easier to remove the crostata later. Roll out the dough to a 14-inch circle on the floured countertop, flipping the dough occasionally to prevent sticking to the countertop and using additional flour as needed. You should always be able to move your dough around the countertop without it sticking. Transfer to the parchment-lined baking sheet. (I like to fold the pastry in half and then half again and then unfold it on the parchment.)
Sprinkle the dough with the almond meal or cookie crumbs, leaving a 2-inch border uncovered. Pour the fruit and juices onto the the almond meal. Brush the border of the dough with egg. Lift about 2 inches of dough over the tart and pinch closed. Keep lifting and folding dough until a 6-inch circle of fruit remains uncovered. Brush folded border with egg. Sprinkle with raw sugar if desired.
Bake in the preheated oven for 45-55 minutes or until the fruit is bubbling and the crust is a beautiful golden brown. Slide the crostata and the parchment to a cooling rack and allow to cool to just warm or room temperature.