Preheat oven to 350°. Line a 15x10 inch rimmed baking pan with nonstick foil.
Arrange cookies evenly across pan.
In a large microwave-safe mixing bowl (I used a Pampered Chef Batter Bowl), heat the butter until melted, then whisk or stir in brown sugar.
Microwave 2 minutes, stirring every 30 seconds, until mixture is slightly thickened and looks more like a caramel sauce. It will still be fairly thin and pourable. Pour sauce over cookies, covering each completely.
Bake at 350 for 10 minutes or until caramel is very hot and bubbly. Remove from oven and let cool on a wire rack very briefly -- just about 3 minutes or until caramel settles down.
Sprinkle chocolate chips evenly over hot caramel. If desired, set another rimmed pan on top of the first rimmed pan to help hold in the heat. Let stand 5 minutes to soften chips, then spread softened chocolate chips over caramel. Sprinkle almonds over the top.
Refrigerate baking pan until chocolate and caramel have hardened, about 1 hour. Break or cut bark. Note: To toast nuts, bake in a shallow pan in a 350° oven for 5-10 minutes or cook in a skillet over low heat until lightly browned, stirring occasionally.