Preheat the oven to 350℉. Spray a 15x10x1-inch baking pan with nonstick spray.
In a large bowl, use an electric mixer to cream together the sugar, butter and salt until light and fluffy. Mix in the eggs, one at a time, then mix in the vanilla. Gradually add the flour.
Spread 3 cups of the dough into the prepared baking pan. Spread the pie filling on top. Drop teaspoonfuls of the remaining dough over the filling.
Bake for 30 to 35 minutes, until golden brown. Cool in the pan on a wire rack.
ADD THE GLAZE:
In a medium bowl, whisk together the glaze ingredients. Drizzle on top of the baked bars and let it settle into all of the nook and crannies. Let set, and then cut and serve.