Whisk together the sugar, cornstarch, and salt in a medium-sized saucepan. Use a blender to blend the egg until well beaten. In a large measuring cup or bowl, add the milk and the beaten egg. Stir to blend.

Pour the milk and egg mixture into the pan and whisk to blend. Using medium-low heat, bring the mixture to a boil, stirring constantly.

Remove the custard from the heat and add butter and vanilla. Stir until well mixed.

Place 1/3 of the pudding into the bottom of six 1-cup serving bowls.

Add 1/3 of the crushed vanilla wafers on top of the pudding in each bowl.

Using one can of blueberries, divide it between the six bowls and place it on top of the crumbled cookies.

Repeat the layers again using another third of the pudding, half of the crushed cookies, and the other can of blueberries.

Add the last third of the pudding on top of the blueberries. Sprinkle the rest of the cookies on top. When ready to serve, garnish with whipped cream and fresh blueberries. May be served warm or cold. Store leftovers in the refrigerator.