In a blender, add all of the crepe ingredients. Blend for approximately 1-1 ½ minutes (or until all the lumps are gone), making sure to stop half-way through to scrape down the sides.
Place the blender in refrigerator and chill for 30 minutes up to overnight. Once the batter is chilled, take a whisk and beat the batter to remove any excess lumps or clumps that may have formed during the chilling process.
Over medium heat, melt ½ teaspoon of butter in a 9-inch skillet. Once the butter has melted, tilt pan to approximately 45-degree angle and pour about 2 tablespoons of batter into the skillet. Be sure to swirl the batter around in the bottom of the skillet to even the crepe out.
Cook for about 45 seconds, or until you see the edges start to turn a golden brown. Then flip and cook for another 15 seconds.
Once the crepe is done, place on a paper towel lined plate and repeat the process starting by melting ½ teaspoon of butter in the nonstick skillet over medium heat. Continue until the batter has been used up.
At this time, you can either continue on to assemble the cake, or place the crepes in a zip-lock bag and store them in the fridge for a day or two prior to making the cake (just be sure to let the crepes come to room temperature again before you begin building the cake).
Once you’re ready to assemble the cake, beat your heavy cream until it’s soft and fluffy. Add in the mascarpone and maple syrup and continue beating until stiff peaks form.
Place a crepe in the center of a cake stand. Spread on a very thin layer (about 1-2 tablespoons) of the cream mixture. Add on another crepe, then another layer of cream, and continue on until all the crepes have been used, making sure to end with a slightly thicker layer of cream on top.
Garnish with pistachios and flowers, if desired, and slice and serve.