Instructions

• Make the custard: In a medium saucepan, combine 3/4 cup granulated sugar, 2 whole eggs and 3 egg yolks. Whisk vigorously about 1 minute until blended.
• Whisk in 1/3 cup corn starch until the mixture is smooth and free of lumps.
• Whisk in 1/2 cup sweetened condensed milk until incorporated.
• While whisking, slowly pour in 3 cups milk (2% or whole) and whisk until smooth.
• Place the saucepan over medium heat. Whisk frequently and continuously until the mixture thickens and just begins to boil (about 8–10 minutes). Remove from heat immediately.
• Off the heat, whisk in 1 tablespoon vanilla extract. Add 1 stick (1/2 cup) unsalted butter, softened, and whisk until fully incorporated and smooth.
• Cover the custard surface directly with plastic wrap (press the wrap onto the surface so a skin does not form). Let sit at room temperature for 1 hour, until the custard is just barely warm.
• While the custard cools, prepare the cookies: If needed to fit your pan, cut large palmiers in half. To do this, stack a few cookies and carefully saw through them with a serrated knife.
• Reserve 3–4 cookies in a large zip-top bag and crush them with a rolling pin to make crumbs for coating the finished cake. (You can crush more later if you want extra crumbs for the top/sides.)
• Prepare your pan: For a 9" springform, remove the base and place the tightened ring in the center of a cake platter. For a 9x13 glass casserole dish, leave it as is on the counter.
• Assemble the cake: Spread about 4 heaping tablespoons of custard into the center of the pan (or inside the springform ring) and hold the ring steady. Arrange whole or halved palmiers in a single layer across the bottom so the base is covered. Break or trim cookies as needed to fit snugly.
• Dollop about 5 heaping tablespoons of custard over that cookie layer and spread evenly with a spatula to cover the cookies.
• Repeat alternating layers of cookies and custard until you have four layers of cookies total. Each cookie layer should be covered with custard.
• Spread any remaining custard over the top, smoothing to seal gaps and cover the top layer of cookies completely.
• Cover the assembled cake with plastic wrap and refrigerate overnight (or at least several hours) to set.
• To finish, remove the cake from the refrigerator. If using a springform, run a thin spatula around the inside edge to loosen, then release and remove the ring. If using a casserole dish, run a spatula around the edge if needed to loosen.
• Sprinkle the reserved crushed cookies over the top and gently press crumbs onto the sides to adhere.
• Arrange berries on top to decorate. Slice and serve.