Whisk together flour, cinnamon, and salt. Set aside.

Beat together butter, sugar, and zest in a bowl of a stand-up mixer with a paddle attachment. Mix until fluffy about 3 min.

Gradually add in flour mixture on low in 3 separate batches. Mix until well incorporated and then add in the pistachios and cherries.

Gather up the dough and divide it into two separate mounds on plastic wrap. Using the plastic wrap shape into a log about 1 1/2" in diameter. Now shape the log into a square shape by rolling onto aside and pressing slightly.

Wrap the logs in foil and freeze until ready to use. Thaw slightly and paint with the egg, roll in sprinkles, and slice into 1/4" thick slices, rotating the log so that it stays square.

Place slices on parchment-lined cookie sheets and bake at 350F for 15 min. or until golden brown.

Let cool on cooling racks.