For the coffee cream,

In a bowl with a whisk, mix the yolks and the egg until they are foamy, add the sugar (70 grams) and cornstarch and mix until it is all incorporated.
In a medium saucepan heat the milk with the butter, remaining sugar, (70 grams) and salt, stir to dissolve the sugar. Just as it begins to boil, remove from heat and add slowly to the yolk mixture, whisking all the time.
Return the mixture to the saucepan and cook over medium heat until it gets thick, stirring all the time. Remove from heat, add the coffee extract and pass through a sieve if you see lumps. Cool the custard over a bowl with water and ice. Cover with plastic wrap pressed directly into the custard. Refrigerate until ready to use. You may make it 2-3 days before use.

For the cake,

Place the milk, eggs, flour, sugar, salt, and bourbon in the blender. Process for 15 seconds. With a spatula, clean the sides of the jar to ensure that all the flour mixes. With the blender on low speed add the butter. Blend for 10 seconds. Refrigerate overnight.

Let the batter return to room temperature. Heat over medium heat in an oiled 8″ non-stick pan. Once hot add 1/4 cup batter, move to cover the entire bottom of the pan. Cook 30 seconds to 1 minute, until the crepe, is golden brown, lift the edges with a knife or spatula and using your fingers to turn the crepe and cook 30 seconds to 1 minute on the other side.
Stack on a plate and let cool completely before using it.

To assembly the cake,

Whip the cream using a cold bowl, beat until hard peaks forms. Mix with gently with the coffee custard.

Fill the cake, alternating pancakes and coffee cream, place a thin layer of cream over the middle and thicker at the edges. Decorate. Keep in the refrigerator.