Double Chocolate Pecan Cookies

1 cup butter, room temperature
1 cup brown sugar, packed
2 large eggs
1 1/2 tsp vanilla
2 cups flour
1 tsp baking soda
1/2 tsp baking powder
2 cups rolled oats
1 cup shredded coconut
4 oz white chocolate chunks
4 oz dark chocolate chunks
6 oz pecans, coarsely chopped

In the bowl of a large electric mixer, cream together butter and brown sugar until light and fluffy. Add eggs, one at a time, followed by vanilla.
In a separate bowl, sift together flour, baking soda and baking powder. Add to butter mixture in thirds, until incorporated. Mix in oats, coconut, chocolate chunks and chopped pecans. These final additions may have to be done by hand, using a stiff wooden spoon, if your mixer isn't powerful enough to cope with the dense mixture.
Drop cookie dough by heaping tablespoons onto Silpat-lined cookie sheets and bake at 350F for about 12 minutes, until just beginning to turn golden. Let cookies cool on baking sheet for a couple of minutes before transferring to a cooling rack. Repeat with remaining dough. Makes approximately 3 dozen cookies.