1-In a large bowl, mix 1 cup: In a large bowl, mix 1 cup softened butter, 3/4 cups brown sugar, and 1/2 cup granulated sugar using an electric hand mixer.
2-Now mash up 2 bananas using a: Now mash up 2 bananas using a potato masher or a fork and add it to the butter mixture along with 2 eggs and 1 teaspoon vanilla extract. Beat that on medium speed until well combined.
3-Hold a fine-mesh sieve over the bowl: Hold a fine-mesh sieve over the bowl of the banana and butter and add in 2 cups of all-purpose flour, 3/4 teaspoon baking soda, 1/2 teaspoon salt, 1 1/2 teaspoon cinnamon, and 1/4 teaspoon nutmeg. Then sift the dry ingredients in, and mix together at low speed.
4-Now add 3 cups of old-fashioned rolled: Now add 3 cups of old-fashioned rolled oats along with 1 cup of semisweet chocolate chips. At this point mix everything together with a spatula.
5-Line a baking sheet with parchment paper: Line a baking sheet with parchment paper and scoop out mounds of the banana oatmeal cookie dough using a medium cookie scoop.
6-At this point, you can round them: At this point, you can round them balls in your hands or top with chocolate chips (optional). Now bake at 350 degrees Fahrenheit for 8-9 minutes.