Preheat the oven to 400 degrees F (200 degrees C). Grease a 6-cup muffin tin or line cups with paper liners.

Pour evaporated milk, flour, 1 cup sugar, eggs, and vanilla extract into a bowl. Stir until there are no chunks. Pour batter into the prepared muffin tin. Use a spoon to make a divot in the center of each cupcake.

Bake in the preheated oven until a toothpick inserted in the center of a cupcake comes out clean, about 30 minutes. Allow to cool completely, about 30 minutes more. Cut cupcakes in half horizontally.

Spread 1/2 cup of whipped cream on the cut surface of the bottom half of each cupcake. Replace the top of each cupcake. Refrigerate filled cupcakes for 10 minutes.

Combine strawberries, blueberries, and blackberries in a bowl. Mix in remaining 1 cup sugar and remaining 1 cup whipped cream. Spread mixture equally on top of the cupcakes. Refrigerate for 10 minutes. Serve chilled.