Sometimes it's fun to have cookies the size of your face--these are 5 inches in diameter! For smaller cookies that are still impressive, use a 1/3-cup measure to portion the dough for 15 or 16 cookies.
Preheat oven to 375°. Line cookie sheets with parchment paper. Place an oven rack in top third of oven. In a large bowl, whisk together flour, rolled oats, baking soda, salt and cinnamon.
In a stand mixer, cream butter and sugars on medium-high speed until light and fluffy, about 3 minutes. Add eggs and vanilla; beat on medium-high speed until combined.
Add flour mixture and mix on low just until combined. Add chopped chocolate and dried cherries; mix again just until combined. (If not baking right away, cover and chill dough several hours or overnight.)
Measure out 1/2 cup cookie dough. Form into a ball and place on prepared cookie sheet. Flatten slightly. Repeat until you have four cookies on each cookie sheet. Sprinkle with flaky sea salt.
Bake cookies until nearly set in centers, 14 to 15 minutes, rotating cookie sheets once halfway through baking. Cool cookies on cookie sheets on a wire rack 10 minutes. Transfer cookies to wire rack; cool completely. Repeat with remaining dough. Store cookies in an airtight container.