1. Preheat the oven to 350°F.
2. Line a 9×9-inch square baking dish with aluminum foil. Grease the foil with butter and set it aside.
3. Using a mixer, cream together the butter, sugar, and egg in a bowl. Then add in the flour and mix a bit more.
4. Continue mixing the dough ingredients until the mixture is a crumbly dough. Then set aside 2 cups of the dough for the top layer.
5. Press the remaining dough onto the bottom of the baking dish to create the bottom layer.
6. Spread the preserves over the dough keeping it within 1/2 inch of the edge.
7. Take the remaining dough and crumble it over the preserves, gently pressing it with your fingers until the top layer is complete. 
8. Bake for 40-50 minutes or until lightly browned.
9. While the bars cool, start making the drizzle.
10. In a bowl, mix the powdered sugar with 1 teaspoon of milk at a time and stir until almost smooth.
11. Melt the white chocolate in the microwave on medium power, 10 seconds at a time, stirring in between, until melted.
12. Add the white chocolate to the powdered sugar and milk and continue mixing until the drizzle is smooth. If it’s not smooth, return the drizzle to the microwave for 10 seconds, remove and stir some more.
13 Lift the cookie bars with the foil from the baking dish and set them on a counter. 
14. Drizzle the bars with the white chocolate drizzle. Let them cool and cut them into squares and serve