From Kathryn Wilson, adapted from a King Arthur Baking recipe
16 Tablespoons butter, softened
1 cup granulated sugar
1 cup light brown sugar, packed
1 teaspoon baking powder
1 teaspoon baking soda
1¼ teaspoons salt
2 large eggs
1 teaspoon vanilla extract
2½ cups old-fashioned rolled oats
2/3 cup white chocolate chunks or chips
2 cups all-purpose flour
1 cup peanut butter chips
1 cup semisweet or bittersweet chocolate chips
1½ cups chopped pecans or walnuts
Preheat your oven to 375 degrees. Lightly grease (or line with parchment) four baking sheets, or as many as you have.
Beat together the butter, sugars, baking powder, baking soda and salt. Beat in the eggs and vanilla.
Using a blender or food processor, process the oats with the white chocolate until the oats are finely ground, and the chocolate is mostly ground; a few small chunks are okay.
Add the oats and flour to the butter mixture, then stir in the peanut butter chips, chocolate chips, and chopped walnuts. Drop the dough by tablespoonfuls, 2 inches apart, onto the prepared baking sheets. Bake the cookies for about 12 minutes, until they're just set. They may be barely starting to brown around the edges, but the tops won't be brown at all. Remove the cookies from the oven, and cool.
These are great to make ahead and store in the freezer. Scoop out the dough onto a wax paper-lined cookie sheet, putting them very close together. Wrap well and freeze for up to two months. They can be baked straight from the freezer, or let them sit on the counter for 30 to 45 minutes, well spaced.
Peanut butter chips can be replaced with dried fruit, such as cranberries, or with other flavors of chips such as butterscotch or cinnamon. The nuts are optional.