Make the filling: Combine the cherries, granulated sugar, lemon juice and a pinch of salt to a boil in a small saucepan over medium heat; bring to a boil. Reduce the heat to a simmer; cook, stirring, until the juices are reduced, about 10 minutes. Mix the cornstarch with the water in a small bowl, then stir into the pan and cook until thickened, 1 to 2 minutes. Remove from the heat and stir in both extracts. Spread on a plate to cool.
Meanwhile, make the topping: Combine the oats, flour, brown sugar, almonds and remaining 1/2 teaspoon salt in a bowl. Work in the butter with your fingers until the mixture is crumbly. Chill until ready to use.
Make the brownies: Preheat the oven to 350˚. Line a 9-by-13-inch baking pan with foil, leaving a 2-inch overhang on all sides; coat with cooking spray. Melt the chocolate and butter in a saucepan over medium heat, stirring. Remove from the heat; whisk in both sugars. Whisk in the eggs and both extracts. Whisk both flours and the salt in a bowl, then whisk into the batter.
Spread the batter in the prepared pan. Top with the cherry filling, then the crumb topping. Bake until a toothpick inserted into the center comes out mostly clean, 45 to 55 minutes. Let cool slightly in the pan, about 20 minutes. Carefully lift out of the pan using the foil overhang and transfer the brownies to a rack to cool completely. Cut into pieces.