Combine all the ingredients in a blender and blend until smooth. Chill in the refrigerator at least 2 hours up to overnight. Bring to room temperature before cooking. The batter will be very thin

Prep several cookie sheets with parchment paper. Heat a 8-10” flat skillet over medium heat. Brush with melted butter and with one hand holding the pan, slowly pour ⅓ c batter in the middle while swirling the pan with the other hand. Cook 2-3 min, using an 8 “ off set cake spatula gently slide it under the crepe, flip and cook another 30 seconds and remove to one of the prepared sheets to cool. Repeat with remaining batter. Once the crepes are cool you can stack them on top of each other to make more room for more.

In a medium saucepan combine the juice, soda, butter and sugar and stir well until the sugar is dissolved. Add the zest, stir again and bring to a boil. Lowed the heat and simmer until reduced and thickened. If you want it a bit thicker mix the arrowroot starch with a little water until thin and then add to the saucepan. Bring back to a boil until thick. Once its reached desired consistency like a thick syrup, transfer to a bowl, mix in the Grand Marnier and add in the orange slices turning gently a few times. Cover with plastic wrap, pressing it against the surface of the sauce and chill overnight. Removed the orange slices when ready to use, wiping off some of the excess sauce back into the bowl.

In a medium bowl combine the yolks, flour and granulated sugar, vanilla bean seeds and whisk. Set on the counter next to your stove. Set out a strainer that fits the bowl. Heat the milk in a small saucepan over medium until it reaches a simmer. Slowly pour the milk into the egg yolk mixture, whisking constantly to temper the eggs. Make sure its all combined, whisking well and then add back to the saucepan and heat over medium low, stirring slowly with a spatula until thick, almost custard like. Strain the mixture into the bowl scraping along the strainer to pass all the pastry cream through. This is in case any of the egg yolk scrambles while the pastry cream cooks and you don’t want that in the cream. Clean the spatula and scrape the cream off the underside of the strainer. Stir in the vanilla extract and cover with plastic wrap , pressing against the surface of the cream and refrigerate until well chilled. Once its fully chilled set out a bigger bowl and pour the heavy cream in and whip until thick, not quite stiff peaks. Add in the powdered sugar and vanilla and whip until very stiff. Fold in the pastry cream until no streaks are left. Chill until ready to use.

On a cake plate or using a cake circle place one crepe and top with 2 heaping tablespooons of the pastry cream, spreading thinly. Place another crepe on top and repeat. The last crepe won’t have pastry cream on top. Chill for an hour or two. Once ready to serve ladle the orange butter sauce on top, letting it drip down the sides and arrange orange slices on top. Save leftover orange sauce for another use or to ladle over slices once cut.