In a small saucepan, add the milk and put over medium heat. Allow the milk mixture to heat until 140°F on a drink thermometer. Remove from the heat. While the milk is heating, continue on to the next steps, but keep an eye on the milk.

In the bowl of a stand mixer fitted with the whisk attachment, add the egg yolks and cane sugar. Whisk on low for 2 to 3 minutes or until lightened in color. Add in the flour and whisk to combine completely.

Once the milk has heated, turn the mixer on low and slowly add in the warm milk into the egg mixture. Once completely combined, stop the mixer.

In a clean saucepan (do not use the one the milk was heated in, incase milk stuck to the bottom, that will burn if used without cleaning), pour in the egg mixture. Put over low/medium heat.

Continue to heat while continuously stirring with a high heat spatula by scraping the bottoms and the sides. The mixture will start to rise and may bubble, continue to stir. The mixture will start to thicken, and continue to stir. The trick is to keep stirring so clumps do not form, as you want a smooth custard. If you see clumps beginning to form, stir vigorously and they will dissolve.

Add in the butter, and stir to combine completely. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, add the heavy whipping cream, cane sugar, and vanilla extract. Mix on low and gradually increase the speed as the whipped cream starts to thicken, until you are full speed. Whisk until stiff peaks form.

Store in the fridge, in an airtight container for up to 5 days.