Preheat oven to 350°F and line 2 baking sheets with parchment paper.
Remove the stems from the maraschino cherries, then pat them dry to remove all excess liquid. Chop the cherries into small pieces then pat dry again, thoroughly.
In the bowl of a standing mixer with the paddle attachment or a handheld mixer, combine butter and sugars, mixing until light and fluffy (1-2 minutes).
Add in the egg and vanilla extract, and beat until just combined (do not over-mix!).
Mix in the dry ingredients until a dough forms. Add in the chopped dark/semisweet chocolate and chopped maraschino cherries and stir until combined.
Use a medium cookie scoop or spoon to make 1.5-2 tbsp sized balls and place them on the baking sheet around 3-4 inches apart. Add a few more chocolate pieces on top if desired.
Bake the cookies (one sheet at a time for even baking) for 8-11 minutes. Remove them from the oven when the edges look set. They will look under-baked in the middle!
Remove from the oven, sprinkle some flaky sea salt on top, and leave them on the baking sheet for 5 minutes, then transfer to a cooling rack to cool completely. Enjoy!
Video
Notes
Measuring Flour: Properly measure your flour using either a kitchen scale or by fluffing it up in the bag with a fork, then using a spoon to scoop the flour into the measuring cup and then use the back of a butterknife to level it off (the is the scoop and level method)Chopped Chocolate: You can also use chocolate chips. I recommend semisweet or dark.Maraschino Cherries: I like to use maraschino cherries made without corn syrup or red dyes, as they have more real cherry flavor and aren't quite as sweet.Storage and Freezing:Store the cookies in an airtight container or ziploc bag at room temperature for 5-6 days.The baked cookies can be frozen in a freezer bag for up to 2 months. Thaw at room temperature when you're ready to eat them.