With a sharp paring knife, cut the stem and tip end off of the oranges and lemons, cutting through the pith (aka the white part) to expose the fruit on both ends. Perpendicular to the cut ends, make 4 evenly spaced slices all the way through the rind to divide the peel into quarters. Use your fingers to carefully peel the sections of rind and pith away from the fruit. On a cutting board, use the back of your knife to scrape some of the pith away from the rind (the less pith you leave, the sweeter the peel will be.) Then, slice the rind into strips. (I twisted some of my strips of peel to give them a curly shape!)

Add the peels to a pot and cover with cold water by 1 inch. Bring to a boil over high heat, then reduce the heat and simmer 15 minutes. Drain, and return the peels to the pot.

Add 1 cup water and 1 cup sugar to the pot with the peels. Over medium-high heat, bring to a boil and stir occasionally to dissolve the sugar. Reduce heat as needed to maintain a simmer for 45-60 minutes, stirring occasionally.

Spread a generous amount of sugar on a rimmed baking sheet, then use a slotted spoon to transfer the peels from the pot onto the sugar. Toss to coat, then spread the sugared peels on a wire rack. Let dry uncovered on the wire rack 1-2 days.

In a small pan over low heat, melt the butter and cook until lightly browned. Pour into a heatproof dish and allow to cool slightly.

Return the pan to low heat, and add the milk. Warm the milk until steaming, then remove from heat and allow to cool slightly.

In the bowl of an electric mixer, mix together the eggs, flour, sugar, and salt at low speed. With the mixer running, slowly pour in the warm butter and the warm milk and mix until just incorporated.

Transfer the batter to an airtight container and refrigerate overnight.

In a medium bowl, whisk together the egg, egg yolks, cornstarch, sugar, and salt. Keep the whisk in the bowl and arrange the bowl on a slightly damp dish towel and set aside. (The damp towel will help keep the bowl from moving or sliding while you are whisking later.)

In a small saucepan, heat the milk and the citrus zests over medium heat until steaming.

While whisking the egg mixture vigorously, pour 2/3 of the steaming milk mixture into the egg mixture. Then, while whisking the remaining steaming milk in the pot vigorously, pour the egg mixture back into the pot. (This back and forth process will temper the hot milk into the eggs. Otherwise you will make scrambled eggs!)

Move the pot back on to the stovetop over medium heat, and bring to a bubbling boil while whisking continuously. Once the pot is boiling, reduce heat to low and cook 1-2 minutes more.

Remove the pastry cream from the heat and stir in the butter 1 tablespoon at a time, waiting until each tablespoon of butter is melted and incorporated before adding more.

Strain the pastry cream through a fine mesh sieve into a fresh bowl. Wrap tightly and allow to cool to room temperature, then store in fridge to chill overnight. (The pastry cream must be covered or it will form a skin on the surface that will form lumps when stirred.)

Chill the bowl and beater of a stand mixer in the freezer for 15 minutes. Add the heavy cream and sugar to the chilled bowl and whip to stiff peaks with the chilled beater. Store the whipped cream, covered, in the refrigerator for up to 12 hours before using.

Brush a 10” nonstick pan lightly with a neutral oil (such as canola) over medium-low heat.

With one hand, lift the pan off of the heat and tilt downward slightly. Add about 3 tablespoons of crepe batter to the back of the pan (nearest to the pan’s handle.) The batter will run down the center of the pan, then quickly swirl the rest of the batter around the pan to form a thin crepe. (If you end up with holes, just patch with a little more batter and swirl to distribute.) Tip: use a ¼ cup measuring cup filled three-quarters of the way to scoop about 3 tbsp of batter.

Cook the crepe about 1 minute until bottom is ‘dry’ and slightly golden brown in places. Look for bubbles, a dry surface, and just slightly browned edges before turning.

Using clean fingers, flip the crepe and cook about 5 seconds more. Transfer the crepe to a sheet of parchment to cool.

Repeat this process to make a total of 20 crepes, brushing the pan lightly with oil between each crepe.

Note: You may need to adjust your heat between medium and low as you cook your crepes, depending on your stovetop. If your crepes are cooking too slowly, increase the heat. Also, you should have enough batter to make at least 10 practice crepes if needed, so don’t fret if they aren’t all perfect.

Fold together the whipped cream and the pastry cream until just combined. Spread a thin layer of the cream between each crepe, not using so much cream that it spills out when another crepe is placed on top. When all of the crepes and cream have been layered, refrigerate the cake 30-60 minutes for best results when slicing.

To serve, dust the cake with powdered sugar and top with the candied citrus peels. This cake is best eaten the same day it is made. Enjoy!