2/3 cup raspberry puree, strained
2 cups heavy whipping cream
Fresh raspberries and powdered sugar to garnish (optional)
Make crepe batter: Blend eggs, milk, granulated sugar, and vanilla in a blender until smooth and frothy. (If you have a small blender, you may have to do this in two batches.) Add flour and ½ teaspoon salt and blend just to combine.
Transfer to a large bowl, cover and chill at least 1 hour or overnight.
Make filling: In a small bowl, combine egg, flour, sugar, and cornstarch; whisk until smooth.
In a saucepan over low heat, bring milk to a simmer, then remove from heat and slowly whisk it into the egg mixture. Return all ingredients to the saucepan and whisk constantly for about 5 minutes until thickened.
Remove from the heat. Add vanilla extract and hot water; stir until dissolved into the mixture. Refrigerate mixture until thick and cool, about 2 hours.
Prepare crepes: Heat a large nonstick skillet over medium heat. Then brush lightly with some butter. Whisk batter to reincorporate and ladle quarter cup into skillet. Working quickly, swirl pan to evenly coat just the bottom of the pan. Cook crepe, reducing heat if browning too quickly, until bubbles form on surface and edges are light golden, about 2 minutes.
Slide a spatula underneath to loosen and carefully flip. Cook on other side until a few brown spots appear, 15 to 30 seconds; transfer to a flat plate.
Repeat with remaining butter and batter, stacking crepes on plate as you go (you should have 20 total). Let crepes cool.
Assemble cake: When the pastry cream is cold and firm, make whipped cream by beating the heavy cream until stiff peaks form. Fold in the pastry cream and the raspberry puree.
Place one prepared crepe on a large cake plate. With a small spatula, completely cover the crepe with a scant ⅓ cup of the pastry cream mixture.
Cover with another dry crepe and repeat with pastry cream mixture and then another crepe, until you have reached 20 layers. Save the nicest looking crepe for the 20th (top) layer. If your layers seem uneven or your cake seems tilted at all, adjust your filling to even it out.
Refrigerate the prepared cake for 1 to 2 hours. Top with fresh raspberries and a sprinkle of powdered sugar if desired. To serve, cut with a chef’s knife into 3-inch wedges so the cake stands up on the plate.
Makes 1 cake.
— Adapted from bonappetit.com