Heat oven to 375°. Whisk flour, oats, coconut, cinnamon, salt, and baking soda in a bowl. Combine butter and both sugars in a large bowl; beat on medium-high speed with a hand mixer until smooth and fluffy, about 3 minutes. Add eggs and vanilla, beating well until incorporated. Add dry ingredients and mix until just combined. Put confectioners’ sugar in a medium bowl; roll dough into 1½ ounce balls, about 1½" thick. Toss dough in confectioners’ sugar until completely coated and arrange on parchment paper-lined baking sheets, about 2–3" apart. Bake cookies, rotating halfway through, until golden brown and crackled, 10–12 minutes. Let cool completely on the pan.