Preheat the oven to 350°F Line a baking sheet with parchment paper.
In a large bowl, cream together the butter and the sugars until mixture is light in color. Beat in the eggs one at a time, followed by the milk and vanilla extract.
In a medium bowl, stir together the flour, baking soda, baking powder and salt. Either by hand or with the mixer on low speed, gradually beat the flour in to the sugar mixture until just incorporated.
Stir in the oats and chocolate chips by hand.
Drop 1 1/2-inch balls of dough onto the cookie sheet, placing about 1 1/2-inches apart so they have room to spread.
Bake at 350° for 10-13 minutes, until golden brown at the edges and light golden at the center.
Cool on baking sheet for at least 1-2 minutes before transferring to a wire rack to cool completely.
Notes: You can substitute raisins for chocolate chips.