Cream the butter, then add both sugars and cream until fluffy. Add the eggs and beat slightly, then add the vanilla and beat until combined. Add the malted milk powder and beat until combined.
In a separate bowl, sift together the flour, baking soda and salt. Add to the butter mixture, beating gently until just combined. Add the chocolate chips and stir in gently.
Drop by teaspoonfuls (or use a cookie scoop) on an ungreased baking sheet, leaving plenty of space between the cookies (they spread out quite a bit). Bake for 9 to 11 minutes. The cookies will be very flat and very chewy. Allow to cool slightly before removing from pan with a spatula.
Optional: Allow to cool completely, then use 2 cookies to make an ice cream sandwich. Add sprinkles to the sides of the ice cream, then wrap individually in plastic wrap.