Prepare a nine-by-13-inch pan by lightly greasing the interior with oil or cooking spray, and set it aside.

Add the ice cream to a large skillet, set over medium low heat. Stir regularly until the ice cream is melted completely.

Reduce the heat to low and stir in the dry milk, making sure to fully incorporate it into the ice cream.

Now, continue stirring constantly, keeping the mixture on low heat for about 15 minutes. Once it has thickened into a sticky paste (kind of a thick fondant texture), remove it from the heat and transfer to the prepared pan. Spread it out evenly and press it flat.

Let the barfi cool completely on the countertop before cutting. I ended up putting mine in the refrigerator and cutting it cold, because it was a little less sticky to do it this way, but it does not need to stay refrigerated.

Store it in an airtight container.