Preheat oven to 350 and prepare cookie sheets by lightly greasing them or lining them with nonstick baking mats.
In the bowl of an electric mixer, cream together butter, vanilla extract, eggs, brown sugar and white sugar.
In a separate bowl, stir together old fashioned oats, baking soda, corn starch, salt and flour.
Add flour mixture to wet mixture and mix until combined. Add sliced almonds, chopped pecans, milk chocolate and peanut butter chips, white chocolate chips and dark chocolate chips and quickly mix to incorporate.
Roll or scoop dough into rounded 1 1/2" balls and place at least 2" apart on prepared cookie sheets. Gently press dough balls down with the palms of your hands to flatten, then bake for approximately 8 to 9 minutes. Don't over bake!
Let cool on cookie sheets for a few minutes, then carefully remove cookies to a cooling rack to cool completely. Store in an airtight container.