Yield: 8-inch crepe cake
Brown the butter. In a small pan, cook the butter until it is fragrant and the milk solids have turned golden brown. Pour into another container and set aside.
In another pot, boil the milk. Turn off heat and allow milk to cool for 10 minutes.
In a stand mixer fitted with a paddle attachment, beat together eggs, flour, sugar, and salt. Slowly add the milk and brown butter. Beat until smooth and well combined. Pour into an airtight container and refrigerate overnight (or at least 2 hours).
In a saucepan, bring milk to a boil. Add tea bags and cover pot. Allow mixture to steep for 30 minutes. Discard tea bags.
Line a quarter-sheet baking pan with plastic wrap, making sure the sides of the pan are also covered. Set aside.
Pour 1 1/2 cup milk into a heavy bottomed sauce pot. Add 1/2 cup of sugar. Whisk together. Place over medium-high heat. Stir occasionally to make sure the milk does not burn along the sides or bottom of the pan. Bring to a boil.
Meanwhile, in a medium bowl whisk together egg yolks, remaining 1/4 cup sugar, cornstarch, and remaining 1/2 cup milk. Whisk until smooth.
Once milk has boiled, reduce heat. Slowly add about 1/4 cup of hot milk into cornstarch mixture. Whisk constantly to distribute the heat and temper mixture. Continue to add milk to cornstarch mixture until there are only a couple tablespoons of milk left in the pot. Pour all the egg-milk mixture back into the saucepot.
Whisk constantly over medium-low heat until the custard has thickened. Continuing mixing and let the custard come to a boil to cook out any unwanted cornstarch flavor. Remove from heat. Whisk in butter and salt until smooth.
Transfer the hot pastry cream into the prepared plastic wrapped sheet pan. Spread evenly. Cover with plastic wrap (allowing plastic wrap to touch pastry cream) and freeze for 10-15 minutes until the pastry cream has cooled to room temperature. Remove from freezer and transfer to an airtight container. Place plastic wrap directly on pastry cream to avoid condensation. Let chill in the fridge until ready to use.
Bring crepe batter to room temperature. Use crepe pan 8 or 9-inches in width. Place crepe pan over medium heat. Lightly grease surface with oil and add 3 Tablespoons of batter. Tilt pan in a circular motion to cover the surface of the pan.
Cook until the bottom of the crepe just begins to brown. Flip the crepe using your fingers or offset spatula. Cook on the other side until set (about 5-10 seconds). Flip the crepe into baking sheet. Repeat until you have used all the batter or have at least 20 perfect crepes.*
Whip the heavy cream with sugar and whiskey to soft peaks. Fold whipped cream into pastry cream in three additions.
Lay one crepe on a cake plate. Spread a thin layer of pastry cream over crepe. Cover with another crepe and repeat to make a stack. Save your best looking crepe to place on top.
Chill cake for at least 2 hours before serving. If desired, sprinkle about two tablespoons of sugar on the top crepe and caramelize with torch. Serve immediately.