Using a stand mixer and paddle attachment cream together softened butter, granulated sugar, and sea salt until smooth and creamy (about 3 minutes). Scrape down sides as needed and continue to mix.
Add in beaten eggs and vanilla and mix until combined (about 1 minute or so).
Gradually add in the flour and mix on medium-low until well combined. As you are adding in the flour, add a few drops of food coloring until you get the desired shade of red.
Tightly wrap your dough ball in plastic wrap and chill for at least 2 hours. You can separate it into 2 balls if you prefer to work with smaller batches.
Pre-heat oven to 350 degrees F and prepare a cookie sheet with parchment paper.
Take your dough out of the fridge.
Use some of the extra flour to sprinkle on a clean countertop and turn the dough out onto it.
Sprinkle the dough ball with flour and use a rolling pin to roll the dough out to about ¼ inch thick. Use more of the extra flour as needed to keep the dough from sticking to the counter or rolling pin.
Use a large cookie cutter to cut out “panes” of cookie dough and transfer them to the prepared cookie sheet.
Use a smaller cookie cutter out of the panes and remove them, adding them to the extra dough that you will roll out for more cookies or use them for smaller mini cookies.
Place crushed hard candies in the cutout of the cookie dough panes. You want to fill it nearly full with the hard candy crumbs and be sure it is in an even layer, not mounded in the centre.
Bake for 10 to 12 minutes or until the edges of the cookies just begin to brown and the candies are completely melted.
Remove from the oven and allow to cool completely on the baking sheet before removing.