Whisk cold milk and vanilla pudding mix together in a large bowl until completely smooth, about 2 minutes. Let stand until pudding thickens slightly, about 5 minutes.
Break up donuts into smaller pieces; spread half in the bottom of a trifle bowl. Layer half of the pudding, bananas, strawberries, blueberries, raspberries, and whipped topping over donuts. Repeat layers. Garnish with whipped topping and a few pieces of fruit. Chill until serving.
