Using a medium saucepan, add blackberries, sugar and water; place over medium-high heat. Bring mixture to a boil.

Once boiling, reduce heat to low and simmer for 20 minutes, or until sauce begins to thicken. Using a wooden spoon, stir until blackberries are broken apart and sauce is well combined.

Press mixture through a fine-mesh strainer to remove seeds.

Let mixture cool to room temperature.

Preheat oven to 200°F.

Line 2 baking sheets with parchment paper; set pans aside.

Using an electric mixer fitted with whisk attachment, beat egg whites until foamy.

Add lemon juice, salt and ¼ cup of the sugar; beat until well combined. Add the remaining sugar in 2 more ¼ cup additions, beating after each addition.

Beat egg whites on high until stiff, glossy peaks form (~5-6 minutes).

Drop large spoonfuls of the egg white mixture onto the prepared baking pans. Carefully flatten tops of the meringues with the back of a spoon.

Drizzle 1 tsp of cooled blackberry sauce on top of each meringue; swirl sauce into meringue using a toothpick.

Bake for 2½ hours, or until meringues are dry and crispy on edges. Turn off oven, but leave meringues in oven overnight to set.

Using a microwave safe bowl, add berries, sugar and lemon juice; toss until well combined.

Microwave for 2 minutes, stir and then microwave for 2 more minutes.

Spoon compote over meringues before serving.