Preheat the oven to 350°F. In a large mixing bowl, combine flour, oats, coconut, salt and brown sugar. Add the softened butter and beat at low speed until the mixture resembles coarse crumbs. Stir in the beaten egg and continue mixing until a cohesive dough forms, then fold in the chocolate chips. Reserve about one and a half cups of this dough for the topping. Press the remaining dough evenly into the bottom of a lightly greased 13×9-inch baking dish and bake until set, about ten minutes.

While the crust bakes, whisk together the sweetened condensed milk and corn syrup in a small bowl until smooth. When the crust comes out of the oven, pour the condensed milk mixture over the hot base and sprinkle the toffee bits evenly on top. Crumble and scatter the reserved dough over the filling layer, covering it as uniformly as possible. Return the pan to the oven and bake until the topping is golden brown and edges are starting to set, about twenty-five to thirty minutes. Remove from the oven and allow the bars to cool completely in the pan before cutting into squares.