Preheat and Prepare: Preheat oven to 350F. Spray a 9-inch pie dish very well with cooking spray; set aside. This prevents the pie from sticking and ensures easy removal.

Melt the Butter: In a large, microwave-safe bowl melt the butter, about 1 minute on high power. Wait momentarily before adding the egg so you don’t scramble it. Melted butter ensures a smooth and even crust.

Combine Wet Ingredients: Add the egg, brown sugar, vanilla, and whisk until smooth. Adding the egg after the butter has cooled slightly prevents scrambling.

Add Dry Ingredients: Add the flour, salt, and stir until just combined; don’t overmix. Overmixing can result in a tough crust.   

Form the Crust: Turn batter out into prepared pie dish, smoothing the top lightly with a spatula. Bake for about 10 to 12 minutes or until edges firm up slightly and center will have begun to set up a bit. It’s by no means done, but pie will be returned to oven to bake another 25 minutes or so. Pre-baking the crust ensures it’s sturdy enough to hold the toppings.

Add Chocolate Chips: Remove pie dish from oven, and evenly sprinkle 3/4 cup chocolate chips over the crust. This adds chocolate chunks throughout the pie.

Add Coconut: Evenly sprinkle the coconut. This creates the chewy coconut layer.

Add Sweetened Condensed Milk: Evenly drizzle the sweetened condensed milk (just eyeball it). This adds sweetness and a gooey texture.

Add Caramel Sauce: Evenly drizzle the caramel sauce (just eyeball it). This adds a rich caramel flavor.

Bake Again: Return pan to oven and bake for about 25 minutes, or until there’s slightly bubbling near the edge of dish and the center has dried out some and looks more set. Cookie pie will firm up more as it cools. In the last 10 minutes of baking, watch it like a hawk because the coconut, caramel, and sweetened condensed milk will all be prone to burning; better to underbake than overbake if you’re unsure. Watching carefully prevents burning.

Melt Chocolate for Drizzle: Allow pie to cool in dish on a wire rack while you melt the chocolate for drizzling by adding 3/4 cup chocolate chips to a small microwave-safe bowl and heat to melt, about 1 minute on high power. Stop to check and stir and heat in 10-second increments until chocolate can be stirred smooth. Melting chocolate in increments prevents burning.   

Drizzle Chocolate: Using a spoon (or pastry bag or ziptop bag with corner cut off if you want to be fancier but I didn’t bother), evenly drizzle the chocolate in long vertical lines, parallel to each other, spaced about 1/2-inch apart. Pie doesn’t have to be cooled to add the chocolate drizzle. Drizzling adds a decorative and flavorful finish.

Cool and Set: Allow pie to continue to cool on wire rack for at least 4 hours (or overnight) before slicing and serving. Don’t slice too early because chocolate drizzle needs to set and interior of pie needs to firm up or you’ll have a literal hot mess. Cooling allows the pie to set and prevents a messy slice.