Chocolate chip cookies (without a mixer!)

Recipe modified from http://www.cookingchanneltv.com/recipes/i-want-to-marry-you-cookies-recipe/index.html

1 cup butter
1 1/4 cups dark brown sugar
1/2 cup granulated sugar
1 egg
1 egg yolk
1 teaspoon pure vanilla extract
2 cups flour
1 cup uncooked rolled oats
1/2 teaspoon baking soda
1/2 teaspoon salt
1/8 teaspoon ground cinnamon
1.5-2 cups chocolate chips

Melt the butter over the stove in a large pot. Turn off the heat. Stir in the sugars until well mixed, then place in fridge for 10 minutes to cool. Meanwhile - combine flour, baking soda, salt, and cinnamon.
Remove mixture from fridge. Add eggs and vanilla; mix well. Stir in flour mixture and oats, then chocolate chips.

Form into 1" (or slightly less) balls on parchment paper on cookie sheet. Chill in fridge for 30 minutes or more. Preheat oven to 325, bake for 12-14 (or more)
minutes. Remove parchment paper from cookie sheet and let cookies cool.

These are nice and chewy, not too thin...but I think I might omit the cinnamon next time. It's distracting. I can also see using a little bit less sugar and slightly fewer chocolate chips.
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Next attempt, 1/24: 1 cup packed dark brown sugar, 1/4 cup white sugar, no cinnamon, 1 1/4 cups of chocolate chips. The amount of chocolate chips was good, but there was something off about the taste and texture. More sugar next time, I suppose.