This recipe (from epicurious.com) appeared in Crispy, Crunchy & Nutty on 19 Dec 2008
1 cup all purpose flour
1/2 teaspoon baking soda
1/2 teaspoon cinnamon
1/4 teaspoon salt
10 tablespoons (1–1/4 sticks) unsalted butter, room temperature
1/2 cup sugar
1/2 cup (packed) golden brown sugar
1 large egg
1 teaspoon vanilla extract
1 cup old-fashioned oats
1/2 cup semisweet chocolate chips
1/2 cup milk chocolate chips
1/2 cup white chocolate chips
1/2 cup coarsely chopped fresh or frozen cranberries
2 ounces milk chocolate or white chocolate, chopped (for drizzling)
Position rack in center of oven and preheat to 350° F. Line 2 large rimmed baking sheets with parchment paper. Whisk flour, baking soda, cinnamon, and salt in medium bowl to blend. Using an electric mixer, beat butter and both sugars in large bowl until smooth. Beat in egg and vanilla.
Add flour mixture and oats and stir until blended. Stir in all chocolate chips and cranberries.
Drop batter by rounded tablespoonfuls onto prepared sheets, 2 inches apart. Bake cookies, 1 sheet at a time, until edges are light brown, about 16 minutes. Cool on sheets 5 minutes. Transfer to rack; cool completely.
Stir chopped milk chocolate in top of double boiler until melted and smooth. Using small spoon, drizzle melted chocolate over cookies in zigzag pattern. Let stand until milk chocolate sets, about 1 hour. (Can be made 2 days ahead. Store in airtight container at room temperature.)