Preheat oven to 350 degrees.

Melt Velveeta and mayo over low heat, stirring frequently. When thoroughly mixed and heated, mix cheese/mayo mixture and potatoes in a big bowl, and combine well. It takes a while, since there are so many potatoes and the cheese is pretty thick.

Scoop it all into a 9 x 11 casserole dish and bake for at least 45 to 60 minutes, topping with the bacon after about 1/2 hour or so, since you don’t want the bacon burnt. Bake until the cheese and potatoes begin to brown just a little, for the best taste. Sometimes it takes longer than 60 minutes, but it’s worth it!