Step 1: Prepare the Red Jell-O Layer
In a large heatproof bowl or measuring cup, combine the 2 boxes of red Jell-O and the 1 box of unflavored gelatin. This double-gelatin method is crucial for a firm set with all that alcohol. Pour in the 2 cups of boiling water. Whisk continuously for at least 2 minutes, until the gelatin is completely dissolved.

Step 2: Add the Cold Liquids
Once the gelatin is fully dissolved, whisk in the 1.5 cups of cold water. Then, carefully whisk in the 1.5 cups of peppermint schnapps and the optional 1/2 cup of vodka. The mixture should now be at room temperature. If it’s still warm, let it sit for a few minutes; pouring warm gelatin can cause layers to mix.

Step 3: Create the White Creamy Layer
In a separate saucepan, sprinkle the 2 packets of unflavored gelatin over 1 cup of cold water. Let it sit for 1-2 minutes to “bloom.” Then, place the saucepan over low heat, whisking constantly for 2-3 minutes until the gelatin is completely dissolved. Do not let it boil. Remove from heat and whisk in the entire can of sweetened condensed milk until the mixture is smooth and uniform.

Step 4: Assemble the Shots (Layered Method)
You have two main options for presentation:

• For a Layered Block (to be cut later): Lightly grease a small loaf pan with cooking spray. Pour in about 1.5 cups of the red Jell-O mixture. Carefully place the pan in the refrigerator and chill for 45-60 minutes, until the layer is set to the touch but not rock hard. Gently pour 1 cup of the white condensed milk mixture over the set red layer. Return to the fridge for another 30-45 minutes until set. Continue alternating layers until all mixtures are used, chilling between each layer.

• For Individual Cups: Pour the red Jell-O mixture into individual 2-oz cups, filling them one-third to halfway. Chill until set, about 30-45 minutes. Then, carefully pour the white condensed milk mixture on top, filling the cups the rest of the way. Chill until fully set.

Step 5: The Final Set
Once all layers are poured, cover the entire pan or cups with plastic wrap and refrigerate for at least 4 hours, but preferably overnight. This long, slow set ensures they are firm and easy to handle.

Step 6: The Grand Finale – Unmold and Garnish
For a block, to unmold: Dip the bottom of the pan in warm water for 10-15 seconds. Place a cutting board or platter over the top, invert, and gently shake until the Jello block releases. Use a sharp knife sprayed with cooking spray to cut into neat squares. For individual cups, they are ready to serve.

Step 7: Serve and Enjoy
Arrange the shots on a festive platter. For a final touch, top each shot with a small dollop of whipped cream and a sprinkle of crushed candy cane pieces just before serving.