1 cup butter, softened
1 and 1/2 cups sugar
2 large eggs plus 1 egg yolk
1 teaspoon peppermint extract (or more to taste)
about 10 drops of green food coloring
3 and 1/4 cups all-purpose flour, spooned and leveled
2 teaspoons baking powder
1 teaspoon baking soda
1 teaspoon cream of tartar
1/2 teaspoon kosher salt
12 ounces dark chocolate chips, divided
Preheat the oven to 350 degrees F. Line one or more baking sheets with parchment paper or a silpat.
In a large bowl or stand mixer, beat the butter and sugar together. Scrape the sides and bottom of the bowl, then beat on medium for about 2 minutes, or until light and fluffy.
Add the eggs + yolk, peppermint extract, and food coloring.
In a separate bowl, combine flour, baking powder, baking soda, cream of tartar, and salt. Add to the wet ingredients and combine until the flour is not quite incorporated.
Add half of the chocolate chips to the dough.* Chop the other half coarsely, with a knife or in a food processor.
Add the chopped chocolate to the dough, and mix until just combined.
Cover the dough and refrigerate for about an hour.**
Use a 1/4 cup measuring cup to form balls of dough and shape them into a long oval shape (not a ball shape, think more egg shape). Place them on the cookie sheet (the tall way) lined with parchment paper or a silicone mat. These are very large cookies, I only did 8 cookies per pan.
Bake at 350 for about 8-10 minutes, or until BARELY starting to brown on the edges. The centers should mostly be not-shiny when you take them out, but a little shine is okay.
Let cool 5 minutes on the pan, then remove to a cooling rack.
*I reserved about 1/3 cup of the whole chips and pushed them into the baked cookies immediately after taking them out of the oven.
**Chilling is not mandatory. You can bake them right after you mix it, I tried it. They will still turn out fine. I prefer the texture and flavor after a little chilling though.