Preheat oven to 350°.
Cream together the butter and granulated sugar until light and fluffy. About 1 minute.
Add in the eggs and vanilla. Mix until thoroughly combined.
Next, add the flour and baking powder. Mix until the dough forms.
Add in the canola oil and mix until the oil is fully incorporated into the dough.
Add the Oreo pieces and white chocolate chips, mixing until they are evenly distributed in the cookie dough.
Scoop a generous 1/3 cup of dough for each cookie. Roll each cookie into a ball and then flatten slightly. The cookie will spread slightly while baking.
Repeat with remaining dough.
Bake at 350° for 13-16 minutes. The cookies should spread and the centers of the cookie should look dry and baked, no longer glossy & wet like unbaked cookie dough.
Allow the cookies to cool complexity on the pan.
Once the cookies have cooled, make the Aggie blue mint frosting by first creaming the butter until it is nice and smooth.
Next add in the powdered sugar one cup at a time, mixing until it combines with the butter. You will need to add in a little bit of milk (think a few tsp at a time) while mixing in the powdered sugar to keep it a good frosting consistency.
Once all of the powdered sugar has been incorporated, mix in the finely chopped oreos and mint extract. Mix until well combined.
Lastly, stir a few drops of blue food coloring at a time into the frosting by hand until you've reached your desired color. (I usually use about 5 drops of food coloring.)
Frost each cooled cookie by spreading the frosting onto the top of each cookie.
Chill the cookies in the fridge for at least 30 minutes before serving. Serve chilled.