First, place oats in food processor so they become fine. Place into a medium bowl with flour, baking soda, salt, and ground cinnamon. Stir together. Set aside.

Place butter and sugars into a large bowl of a stand mixer (or just a large bowl and a hand mixer) and beat together until light and fluffy (about 2 minutes). Add vanilla and 1 egg and mix until combined. Add other egg and mix just until combined.

Add all dry ingredients to butter mixture and beat just until combined. Do not over-mix!

Using a spatula, fold in chocolate chips and toffee pieces until evenly distributed. Scoop dough into 2 tablespoon-portions and place on a large baking sheet with parchment paper. Place in fridge for 1 hour to chill before baking.

Preheat oven to 350 degrees. Remove cookie dough from fridge and place onto baking sheets about 2 inches apart. Be careful - these cookies will spread!

Place cookies into preheated oven for 11-13 minutes, or until the edges are nice and crispy. I only bake one sheet at a time and put others into the fridge as they wait to be baked.

Remove from oven and cool on baking sheet for 5 minutes and then transfer to cookie sheet to continue cooling. While they cool, sprinkle a little flaky sea salt over the cookies.

Eat immediately or store them in a storage container for up to 4 days.