I make chocolate/fudge in an 8"x8" baking pan. Once it cools down I cut it into 36 squares. As hard as I try, I was never able to get them as uniform as I wanted. I made this template, and now they come out perfect every time.
To use it you lay the template on top of the chocolate (with the tiny points facing down) and press each of the 20 points into the chocolate, leaving 20 tiny holes. Then you line up the knife over a pair of the holes and make the 10 cuts.
I printed mine in clean PETG, but it probably doesn't matter what you use.
The author marked this model as their own original creation.