Step 1

In a small saucepan, whisk flour into milk and heat, stirring constantly, until it thickens. It will be the consistency of a thick pancake batter. It should not look wet at this point.

Step 2

Remove from heat and let it cool to room temperature.

Step 3

Stir in vanilla.

Step 4

While the mixture is cooling, cream the butter, sugar, and salt together until light and fluffy on medium high, about 5 minutes.

Step 5

Then add the completely cooled milk mixture along with the cinnamon.

Step 6

Beat it for about 5 minutes on medium-high to high until it looks like whipped cream. It may look separated at first, so keep beating it until it comes together and looks like a whipped cream.