Prepare the strawberry cake mix according to package directions. Bake in a greased and floured 9×13 pan according to package directions.
Mix together sweetened condensed milk, evaporated milk, and half-and-half.
Remove cake from oven. Poke holes in warm cake and slowly pour milk mixture over cake. Cool cake completely.
Cover and refrigerate overnight.
When ready to serve, whip together heavy cream, powdered sugar, and vanilla extract. Whip at high speed for 1 to 2 minutes.
Spread over cake and top with chopped strawberries.