Preheat oven to 350°F. Butter and flour two 8-inch cake pans.

In a large bowl, whisk together dry ingredients: flour, sugar, ground cinnamon, baking powder, baking soda, and salt.

Add eggs, oil, vanilla, and milk. Mix on medium speed with an electric mixer until all ingredients are incorporated, 1-2 minutes.

Divide batter evenly between cake pans. Bake for 23-25 minutes or until cakes are golden brown and set in the center. (Test by inserting a toothpick into the center of each cake layer. If it comes out clean, they're done!)

Let cakes cool in pans for 5-10 minutes before turning out onto a wire rack to cool completely.

In the bowl of a stand mixer, beat cream cheese and butter on medium-high speed.

Add milk and vanilla. Gradually add powdered sugar, mixing well and scraping the sides of the bowl as necessary.

Transfer frosting to a piping bag with an open round tip (or just snip the end off of the piping bag).

Add brown sugar and water to a small saucepan over medium heat. Stir or swirl the pan occasionally until sugar is melted. Remove from heat and cool completely.

When brown sugar syrup is cool, beat butter in the bowl of a stand mixer (you can re-use the same bowl as the cream cheese frosting if you’d like!) until creamy.

Add cinnamon, vanilla, and powdered sugar. Mix until smooth and ingredients are completely combined. Mix in the brown sugar syrup.

Transfer frosting to a piping bag with an open round tip (or just snip the end off of the piping bag).

Level cake layers and place one on a cake stand or plate. Pipe alternating circles of cream cheese and brown sugar-cinnamon frosting. Place the second cake layer on top. Pipe alternating lines of frosting around the outside of the cake and on top. Use an offset spatula or bench scraper to smooth the sides of the cake.

Serve cake or store cake in the refrigerator if not serving immediately. Let cake come to room temperature for 15-20 minutes before serving. Store leftovers in the refrigerator for 2-3 days.