Make the Pie Dough
1-Use this recipe for the pie dough: Use this recipe for the pie dough. Once the dough is done wrap the disk in plastic wrap and chill for at least 45 minutes. Freeze the other half of the dough. The dough for this pie can be refrigerated for up to 2 days.

Prepare the Raspberry Filling
2-Place the raspberries in a strainer and: Place the raspberries in a strainer and wash them with a spray of water. Spread them out on paper towels to soak up excess water. Pat the top of the raspberries with a paper towel.
3-Place the raspberries in a large bowl: Place the raspberries in a large bowl and zest the lemon directly into the berries. Add the lemon juice and vanilla extract. Combine the granulated sugar, tapioca, and the salt and whisk together. Add these ingredients to the raspberries and gently fold the sugar mixture, lemon juice, and lemon zest into the berries.
4-While the raspberries are macerating flour a: While the raspberries are macerating flour a working surface. Rollout the dough into a 12-inch circle. As you roll out the dough rotate the dough one-quarter turn after each pass of the rolling pin. If at any time the dough sticks, add more flour to the work surface.
5-Fold the dough in half and lift: Fold the dough in half and lift it onto a parchment paper (18×12-inches). Move the parchment paper with the dough onto a cutting board or the back of a baking tray that is large enough to hold the galette but small enough to fit into your refrigerator.
6-Use a slotted spoon to spoon the: Use a slotted spoon to spoon the raspberry filling into the center of the dough. Once all the berries are added fold the edges of the dough over the raspberries overlapping each fold over one another. There will be juice at the bottom of the bowl. Do not discard this liquid it will be added to the pie right before it goes in the oven.
7-Brush off any excess flour on the: Brush off any excess flour on the dough with a pastry brush. Refrigerate the galette for 30 minutes.

Baking the Galette
8-Preheat the oven to 375°F: Preheat the oven to 375°F.
9-Whisk together the egg and the water: Whisk together the egg and the water to make the egg wash. Remove the galette from the refrigerator and gently transfer to a 18×12-inch rimmed baking sheet. Brush the galette with the egg wash making sure to get under the folds of the dough. Spoon the raspberry juices from the bowl into the center of the raspberry filling. Sprinkle the dough with the sliced almonds and granulated sugar.
10-Place the galette in the oven and: Place the galette in the oven and bake for 35-40 minutes (rotating halfway through the baking time) or until the crust is dark golden brown and the raspberry juices are bubbling. The bake time may vary because of the oven you have.
11-Remove the galette from the oven and: Remove the galette from the oven and place it on a wire rack, Allow to cool to room temperature, about 90 minutes before serving. Allowing the galette to cool will allow the fruit to set and make it easier to cut into nice clean slices.
12-Optional: Optional: After the galette has cooled and right before serving it, mix 1 cup of fresh raspberries with 1 tablespoon of granulated sugar. Spread these berries over the top of the galette or add to each individual serving.
13-Serve the galette with ice cream or: Serve the galette with ice cream or whipped cream or just with the fresh berries.

Storing the Galette
14-The pie can sit at room temperature: The pie can sit at room temperature for 2 days (and for 1 day if the weather is hot and humid) if you don’t add the fresh raspberries to it. If the fresh raspberries are added refrigerate no more than 3 hours after serving it.Store the pie in the refrigerator for up to 4 days, covered with plastic wrap or foil.