Servings: 9 -inch cake For the Napoleon Cake: 800-900 grams Palmier or "elephant ear" cookies, we buy the 2 lb box from Costco 3/4 cup granulated sugar 2 whole eggs + 3 yolks, from large eggs 1/3 cup corn starch 1/2 cup sweetened condensed milk 3 cups milk, 2% or whole milk 1 Tbsp vanilla extract 1 stick, 1/2 cup unsalted butter, softened Berries to Decorate the top What You Will Need: 9 " springform pan, or a 9x13 glass casserole dish Cake platter
In a medium saucepan, combine 3/4 cup sugar, 2 whole eggs and 3 yolks and thoroughly whisk together 1 minute. Add 1/3 cup corn starch and whisk until smooth. Whisk in 1/2 cup condensed milk. Add 3 cups milk while whisking. Once milk is incorporate, place over medium heat and continue whisking frequently until thickened and just starts to boil (8 to 10 min). Remove from heat right away.
Whisk in 1 Tbsp vanilla then add butter and whisk until fully incorporated. Cover custard surface with plastic wrap so a film does not form and let stand at room temperature for one hour until just barely warm.
While custard cools, prep cookies and cut in half if large to fit more in the pan. To slice, stack cookies and saw carefully with serrated knife. For the crumb coat, place 3-4 cookies in a large ziploc bag, seal and crush with rolling pin.
Remove the base of a 9" springform pan and place the tightened ring over the center of a cake platter. Spread 4 heaping Tablespoons of custard into the center, holding the ring steady. Arrange as many cookies as you can fit in a single layer into the bottom of pan**. Cover with 5 heaping Tablespoons custard and spread evenly with spatula.
Spread remaining frosting over the top, sealing any gaps. Cover with plastic wrap and refrigerate overnight. Once you take the cake out of the refrigerator, run a thin spatula around the edge to loosen it from the pan. Sprinkle crushed cookies over top and sides, gently patting to adhere crumbs. Arrange berries over the top and serve.