Melt butter in medium saucepan; remove from heat. Stir in oats, sugar, flour, corn syrup, milk, vanilla and salt; mix well. Drop by level teaspoon about 3 inches apart onto foil-lined baking sheets. Spread thinly with rubber spatula.

Bake in preheated 375 degree oven for 6-8 minutes or until golden brown. Cool completely on baking sheets on wire racks. Peel foil from cookies.

Microwave morsels in medium, microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; stir. Microwave at additional 10 to 20 second intervals, stirring until smooth.

Spread thin layer of melted chocolate onto flat side of half the cookies. Top with remaining cookies, placing flat side against chocolate. Makes about 3 1/2 dozen cookies.