Preheat oven to 375°. Line 4 large cookie sheets with parchment paper. In a food processor, grind the oats until they turn into a fine powder. Coarsely chop the chocolate and add to the oats, processing until the pieces become as fine as possible. Though this takes some time, the finer mixture makes a better cookie. Set this mixture aside. Cream the butter and sugars together in a large bowl. Add the eggs and vanilla and mix well. In another bowl, combine the flour, baking powder, baking soda and salt. Then gradually beat the flour mixture into the butter mixture. Add the oats mixture and blend thoroughly. Work the chocolate chips into the dough. Divide the dough into 48 balls. Place these golf ball-size balls onto the 4 cookie sheets, spacing them evenly. These make large cookies. Bake in the middle of the oven, reversing the sheet halfway through the 11-minute baking time. The cookies will not appear done after 11 minutes, but take them out anyway. Let the cookies cool on the parchment paper, moving them to racks will make them fall apart. Once they are cool, put them in plastic bags and store them in the freezer. Keep at room temperature, they dry out too fast.