Preheat oven to 350 degrees. Spread pecans in a single layer on a rimmed baking sheet. Toast in oven, tossing occasionally, until darkened and fragrant, 10 to 13 minutes. Let cool, then coarsely chop. Into a bowl, sift together flour, baking soda, salt, and baking powder.

With an electric mixer on medium-high speed, cream butter and both sugars until pale and fluffy. Reduce speed to medium. Add eggs, one at a time, beating well after each addition. Beat in vanilla.

With mixer on low speed, gradually add flour mixture, beating until just incorporated. Beat in oats, chocolate, pecans, and coconut until just combined. (Dough can be covered with plastic and refrigerated up to 3 days.)

Coat baking sheets with cooking spray; line with parchment, and spray parchment. Using a 1 1/2-inch ice-cream scoop or a tablespoon, drop dough onto prepared sheets, about 3 inches apart.

Bake, rotating sheets halfway through, until edges of cookies begin to brown, 16 to 18 minutes. Transfer sheets to wire racks to cool 5 minutes. Transfer cookies to racks to cool completely. Cookies can be stored up to 3 days at room temperature in airtight containers