Preheat the oven to 350°F.
Make the crust. Grease the bottom and sides of a 9-x-13-inch pan. Line the pan with a sheet of foil or parchment so it extends over two sides of the pan.
Combine the flour, sugar, and salt in the bowl of a food processor and pulse a few times to blend. Add the butter and pulse just until mixture resembles coarse crumbs. In a small bowl, mix the egg, vanilla and lemon zest. Add to the flour mixture and pulse just until blended and crumbly (do not over process). Scrape the mixture into the prepared pan and press into an even layer.
Make the filling: In a medium bowl, mix the sugar, cornstarch, cinnamon, ginger, and salt. Add the blueberries and toss to coat. Scatter the blueberry mixture over the crust.
Make the topping: In a medium bowl mix the flour, both sugars, the cinnamon, and salt. Add the melted butter and mix with a fork until the mixture comes together. Sprinkle the topping over the filling.
Bake until the topping is golden brown and the filling is bubbling, 45 to 50 minutes. Set the pan on a wire rack to cool completely. Lift the bars out of the pan, using the ends of the foil or parchment. Cut into 24 bars and serve.