Preheat your oven to 350°F (175°C). This ensures that the bars bake evenly.

In a large mixing bowl, combine the flour, sugar, salt, and baking powder. Whisk together until well mixed.

Add the softened butter to the dry ingredients. Using a pastry cutter or your fingers, mix until the mixture resembles coarse crumbs.

Stir in the beaten egg and vanilla extract until the dough comes together. It should be slightly sticky but manageable.

Reserve 1 cup of this dough for the topping, and press the remaining dough evenly into the bottom of a greased 9x13 inch baking pan.

In a medium bowl, combine the pitted cherries, sugar, cornstarch, lemon juice, and vanilla extract. Toss gently to coat the cherries evenly.

Spread the cherry mixture evenly over the crust in the baking pan.

Crumble the reserved dough over the cherry filling evenly. This will create a nice topping that bakes into a crunchy layer.

Bake in the preheated oven for 35-40 minutes, or until the topping is golden brown and the filling is bubbly.

Remove from the oven and allow to cool in the pan for at least 15 minutes before slicing into bars. This helps the filling set up a bit.