This is a small cake but you can make a full size cake by using 2 boxes of puff pastry and not cutting it in half. This will give you 4 square sheets of pastry. Double the recipe for frosting too.
1/2cupunsalted butterunsalted and at room temperature
4ozsweetened condensed milk
1tspvanilla extract
Instructions
Preheat the oven to 400, line a cookie sheet with parchment paper and lightly spray it with some baking spray.
Defrost the puff pastry and cut each square in half. This will give you four layers. Using a fork, poke some holes evenly through the pastry (about 3 times on each rectangle: top, middle, bottom).
Place the puff pastry carefully on the cookie sheet and bake it for about 14-15 minutes.
Cool the sheets of baked pastry completely.
While the pastry is cooling, make the frosting.
In a bowl of an electric mixer, with a whisk attachment, combine butter, condensed milk and vanilla extract. Beat on high for 2-3 minutes. Scrape the sides and bottom of the bowl and the whisk attachment. Beat for about another 2 minutes. The frosting will be very smooth, light and creamy.
Collect all the crumbs from the puff pastry and press it in a few spots to get some extra crumbs. You will use those crumbs for the topping of the cake.
Spread the frosting on top of each pastry layer, even on the top one. Spread the crumbs that you collected evenly over the top layer.