Heat the oven to 350°F. Beat butter and sugar together until fluffy. Add egg and mix well. Add milk and vanilla and mix well.
In a separate bowl, combine flour, oats, baking powder, and salt. Add dry ingredients to wet ingredients and mix until just combined. Stir in the cereals, nuts, and chocolate chips.
Scoop dough into 2 inch balls on a cookie sheet. Bake for 20 to 25 minutes, until the tops are golden brown. Sadly, cookies need to cool before eating. They are definitely better after they cool than fresh from the oven.