HEAT oven to 300ºF.
BEAT peanut butter and sugar in large bowl with mixer until light and fluffy. Combine next 4 ingredients. Add to peanut butter mixture along with milk; beat just until blended. (Mixture will be slightly crumbly.)
ROLL into 30 balls, using about 1 Tbsp. dough for each. Place, 1 inch apart, on baking sheets. Flatten slightly.
BAKE 30 min. or until lightly browned. Cool on baking sheets 3 min. Remove to wire racks; cool completely.
serving size = 1 cookie (23 g)