Step 1

For the cupcakes: Preheat the oven to 350 degrees F. Line a standard 12-cup muffin tin with paper cupcake liners.

Step 2

In a medium mixing bowl, combine the flour, cinnamon, baking soda, baking powder and salt. Set aside.

Step 3

In the bowl of an electric mixer, cream the butter, granulated sugar, light brown sugar, sour cream, vanilla and eggs until fluffy, about 3 minutes. Turn the speed to low and add the dry ingredients. Blend until well combined, about 25 seconds.

Step 4

Pour 2 1/2 to 3 tablespoons of batter into each cupcake liner. Bake the cupcakes until a tester inserted into the center comes out clean, about 20 minutes. Let cool.

Step 5

For the buttercream: Using an electric mixer with the paddle attachment, cream the butter, vanilla and cinnamon until smooth, scraping down the sides as needed, about 2 minutes. With the machine running on low, add the powdered sugar 1 cup at a time, alternating with the milk, and mix until combined. Fit a pastry bag with a star tip and fill with the buttercream.

Step 6

For the tortilla crisps: Mix together the granulated sugar and cinnamon on a large plate. Set aside.

Step 7

In a medium, heavy-bottomed saucepan, add enough oil to come halfway up the sides of the pan. Heat over medium-high heat until a deep-frying thermometer inserted in the oil registers 350 degrees F. (If you do not have a thermometer, test the oil with a piece of tortilla, which should sizzle when it touches the oil and should brown in 2 to 3 minutes.)

Step 8

Meanwhile, using a cookie cutter, cut the tortillas into different shapes and/or letters. Fry the tortilla pieces until golden brown, 2 to 3 minutes. With a slotted spoon, transfer the crisps to paper towels to drain. While still warm, transfer to the cinnamon-sugar mixture and turn to coat.

Step 9

To assemble the cupcakes: Pipe a swirl of buttercream on each cupcake and top with a tortilla crisp.