1
: Preheat oven to 350°F (180°C).
2
: Stir flour and baking powder together. Set aside.
3
: With electric mixer on medium speed, cream butter and brown sugar together until smooth. Add eggs, vanilla and sweetened condensed milk, beating just until smooth. Gradually add flour mixture, beating just until smooth. With mixer on low speed, add oats and chocolate chips mixing just until combined.
4
: If baking immediately, drop about 1½ tbsp (22.5 mL) batter onto parchment lined baking sheet, 2 inches (5 cm) apart. Flatten slightly. Bake 12-15 minutes or until edges just begin to turn brown. Transfer to wire rack to cool and harden.
: For refrigerator cookies :
5
: Divide the dough into 3 pieces. Shape into logs 2" / 5 cm in diameter on parchment paper. Roll up the log of dough in the parchment paper and twist the ends closed. Refrigerate until firm, at least 4 hours or until ready to use, up to 5 days. When ready to bake, cut the log into ½" / 1.2 cm thick slices, and continue as in step #3.Refrigerated dough may take up to 5 minutes longer to bake.