Cookies ‘n Cream White Chocolate Fudge

1 cup granulated sugar

1/2 cup salted butter not margarine

1 5-oz can evaporated milk (2/3 cup)

1 1/2 12-oz packages white chocolate chips (3 cups)

1 7-oz jar marshmallow cream or 1 (10-oz) package mini marshmallows

3 cups coarsely crushed Oreo cookies about 25 cookies, divided