Preheat the Oven:

Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans.

Mix Dry Ingredients:

In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt.

Cream Butter and Sugar:

In a large mixing bowl, use an electric mixer to beat the softened butter and sugar until light and fluffy.

Add Eggs and Vanilla:

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Alternate Wet and Dry Ingredients:

Gradually add the dry ingredients to the wet mixture in three additions, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined.

Bake the Cakes:

Divide the batter evenly between the prepared pans. Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

Prepare the Frosting:

In a large bowl, beat the softened butter until creamy. Add the dulce de leche, powdered sugar, and vanilla extract. Beat until smooth and fluffy.

Assemble the Cake:

Place one cake layer on a serving plate. Spread a generous layer of frosting on top. Place the second cake layer on top and frost the entire cake.

Add the Cinnamon-Sugar Coating:

In a small bowl, mix the granulated sugar and ground cinnamon. Gently press the mixture onto the sides of the frosted cake.

Decorate and Serve:

Pipe extra frosting around the edges or top with a drizzle of dulce de leche for an elegant finish. Slice and enjoy your Bolo de Churros!