Mint Chocolate Oreo Bars

For the Crust:

1. Preheat oven to 350F, line an 8-by-8-inch pan with aluminum foil, spray with cooking spray; set aide.
2. Place Oreos in a food processor with melted butter, and process until very fine. (This can be done by hand by placing Oreos in a large ziplock and rolling over it with a rolling pin or similar heavy object like a coffee can. Transfer crumbs into large mixing bowl, add the butter, and stir until combined).
3. Transfer buttery crumbs to prepared pan, and pack them down using your hands or a spatula.
4. Bake for 10 to 12 minutes, or until just set. The crust is dark and it's hard to determine set from not set, but it will start drying out and getting lighter in color around the perimeter of the pan after about 10 minutes. That's all you're looking for; don't bake longer than 12 minutes or crust will be prone to cracking and crumbling when slicing the bars.
5. Set pan aside.

For the Mint and Chocolate Fudge Layers:

1. Do not start this until crust is out of the oven because it goes fast and you don't want fudge to set up until pan is out of the oven. Work quickly when preparing these layers.
2. Place white chocolate chips in a small, microwave-safe bowl.
3. Place semi-sweet chocolate chips in another small, microwave-safe bowl.
4. Pour half the sweetened condensed milk over the white chips, and the remaining half over the semi-sweet chips; set chocolate bowl aside. Just eyeball dividing the milk, you don't have to measure.

Mint Layer:

1. Heat white chocolate mixture on high power for 30 seconds to melt, stop to stir. Heat in 10-second bursts until mixture can be stirred smooth. Note - white chocolate is notorious for scorching, seizing up, and being finicky. Heat until just melted, no more. Mine took 45 seconds. If it's easier for you to melt over a double-boiler, do so.
2. After mixture is smooth, add the peppermint extract, food coloring, and stir to combine. Work quickly because fudge will start setting up very quickly.
3. Pour mixture over crust layer; smooth it with an offset knife; set pan aside.

Chocolate Fudge Layer:

1. Heat chocolate and sweet milk mixture on high power for 30 seconds to melt, stop to stir. Heat in 10-second bursts until mixture can be stirred smooth. Semi-sweet chocolate may take slightly longer to melt than the white, about 1 minute total.
2. Pour chocolate over mint layer, smooth with an offset knife. It may seem like chocolate is a little skimpy and doesn't fully cover the mint layer, but when it sets up, it will be fine.
3. If desired, make a swirled or marbled pattern by zigzagging very lightly over the top surface of the chocolate with the tip of the knife, taking care not to go very deep and not to blur the mint and chocolate layers together; just make a design in the superficial surface layer for cosmetic appeal (In case your chocolate work was less than perfect, this is a nice camouflage).
4. Sprinkle sanding sugar or sprinkles over the top, as desired, before chocolate fully sets up.
5. Cover pan with aluminum foil to prevent it from taking on fridge smells, and place in the refrigerator for at least 4 hours, or overnight, before slicing and serving; do not slice too early or bars will be a mess.