Place a metal mixing bowl in the freezer. Lightly grease an 8-inch square baking dish.
For the trifle, place the strawberries in a mixing bowl, then toss with the sugar, salt, and lemon juice. Leave in the bowl at room temperature so the strawberries will macerate and become juicy.
Meanwhile, to make the custard, whisk together the milk, heavy cream, sugar, flour, egg yolks, and salt in a medium pot, and then heat on medium-low heat, continuously stirring.
After about 5-7 minutes, it will start to bubble and then thicken. Turn the heat down to low and stir in the butter and vanilla extract. Turn off the heat.
To make the whipped cream, take the bowl out of the freezer, add the cream, sugar, and vanilla then beat the ingredients until soft peaks form.
To compose the trifle, unwrap the Twinkies from their wrappers, then layer the Twinkies in one layer along the bottom of the baking dish. Spoon over it the vanilla custard, then layer over the custard the strawberries and their juices. Finally, spread over the berries the whipped cream.
Refrigerate for at least 2 hours covered then serve chilled. Will keep in the refrigerator for 3 days.
Notes
A small box of Twinkies has 10; the cook is free to eat the one not used in this recipe.