Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius)
In a large bowl, cream together the softened butter and brown sugar.
Add the eggs, vanilla, and milk to the butter/sugar mixture. Combine.
Add the baking powder, baking soda, cinnamon, salt, and flour to the bowl. Mix to combine.
Mix in the oats, pecans, and white chocolate chips.
Add the peeled and diced apples to the batter. Mix to combine.
Drop the batter by rounded tablespoons onto parchment lined baking sheets and bake the cookies in a preheated 350-degree oven for 18-20 minutes or until the cookies are puffed and golden brown.
Cool on a cooling rack and continue the same process with the remaining dough.
Store in an airtight container for up to 1 week, or wrap well and freeze.