Line a 9x13-inch baking dish with plastic wrap, leaving a good amount of overhang on the sides. Break the graham crackers in half and arrange them on the bottom of the pan. To solve the issue of extra space on the side, use a ruler as a "receding wall" underneath the plastic wrap along with a freezer-safe item that'll fit behind it. I used five fun-sized Butterfinger chocolate bars. Click on the link for more in-depth instructions.

In the well-chilled bowl of a stand mixer fitted with the whisk attachment, beat together sweetened condensed milk, cream cheese, and vanilla until smooth. Add in heavy cream and beat on high until mixture is light and fluffy.

Divide ice cream among four bowls and dye each separately to desired shade.** Plop spoonfuls of each colored ice cream randomly over the graham crackers until you've used them all up. Use a knife to swirl the colors together, then smooth out the top. Arrange the remaining graham crackers on top. Wrap the plastic wrap over the ice cream sandwiches and freeze for at least 4 hours, preferably overnight.

Once ice cream sandwiches have frozen solid, remove from the pan and unwrap the plastic wrap. Using a sharp, warm knife, cut the sandwiches along the graham cracker edges, making 15 squares and 5 small rectangles. Place sandwiches on a wax paper-lined baking sheet and return to the freezer to firm up for 20 minutes.

Prepare a second baking sheet by lining it with wax paper. Melt the purple candy melts with the coconut oil in a microwave-safe bowl in the microwave until smooth. Pour the sprinkles into a separate bowl.

Working quickly in batches of 3-4, dip sandwiches halfway into candy melts, then into the sprinkles, and onto the second baking sheet in the freezer. Repeat with the rest of the sandwiches. Once the coating has set, ice cream sandwiches can be individually-wrapped in plastic wrap and stored in the freezer for up to 2 months.