Preheat the oven to 350°F (177°C) and lightly coat a 9x13-inch baking dish with nonstick spray; set aside.
Make the crust: in a large bowl combine 3/4 cup butter (tiny pieces), 3/4 cup brown sugar, 2 3/4 cups all-purpose flour, 1 egg, 1 tsp lemon juice, and 1/4 tsp salt. Use your hands or a pastry cutter to work until the mixture is crumbly.
Press the crumbly dough evenly into the prepared baking dish to form the crust and bake for 15 minutes, then remove and set aside.
Prepare the filling: in a large bowl combine 10 oz sweetened condensed milk, 2 cups shredded sweetened coconut, 1 tsp vanilla extract, and 1/2 cup powdered sugar; mix until well combined.
Carefully spread the coconut mixture over the warm baked crust in an even layer, then return the pan to the oven and bake for 25 minutes more.
Remove the pan from the oven and let it cool for about 1 hour at room temperature.
Scatter the 1/2 cup dry roasted almonds (whole or chopped) evenly over the cooled coconut layer.
Melt the 1 3/4 cups semi-sweet chocolate chips in a microwave-safe bowl in 30-second intervals at 50% power, stirring between intervals, until smooth.
Pour the melted chocolate over the almonds and gently spread to coat evenly. Let cool to room temperature, then slice into 12 bars.