Tear off a large piece of parchment paper. Spread the peanut butter across one half of the paper. Fold over the other half of the paper. With a rolling pin, gently roll the peanut butter to about 1/4-inch thickness. Freeze until solid, at least 3 hours.
Using kitchen shears, cut the parchment paper into squares. Remove the parchment paper and place the peanut butter squares on top of the slices of bread. As the peanut butter softens, you can add honey, sprinkles or whatever you like as a sandwich topper!