1 cup (2 sticks) unsalted butter, room temperature
3/4 cup granulated sugar
3/4 cup packed brown sugar
1 teaspoon pure vanilla extract
2 large eggs, room temperature
1-1/2 cup semi-sweet chocolate chips, chunks, or chopped dark/semi-sweet chocolate
1 cup additional mix-ins: dried cherries, dried cranberries, toasted shredded coconut, broken pretzels, candy-coated chocolates, mini marshmallows, popped popcorn, crisped rice cereal, etc.
Directions
Preheat oven to 375°F and set rack to middle position.
Line a baking pan or cookie sheet with parchment paper.
In a small bowl, whisk together flour, baking soda, salt, and cinnamon.
In a large mixing bowl or the bowl of a stand mixer, blend together the butter, granulated sugar, brown sugar, and vanilla extract.
Add in the eggs one at a time, beating on medium after each addition. Beat until just combined.
Gradually add in the flour mixture and beat again on medium until just combined.
Gently stir in chocolate chips and one cup of additional mix-ins (one cup total additional mix-ins, not one cup of each mix-in).
Cover bowl and refrigerate dough for at least one hour. You can also freeze the cookie dough at this point for future use - either as one large portion, or in pre-rolled balls.
Roll into heaping tablespoon-sized balls and place on prepared cookie sheet/baking pan
Bake for 11-12 minutes or until golden brown. Cool on baking sheets for two minutes and then transfer to cooling racks to cool completely before serving.
Stored in an airtight container at room temperature, cookies will last up to one week.