01 -
Preheat the oven to 175°C. Line a cupcake tin with paper liners.
02 -
Whisk together the flour, baking powder, baking soda, salt, and cinnamon in a medium bowl.
03 -
In a separate large bowl, beat the softened butter with granulated sugar until light and fluffy.
04 -
Add eggs one at a time to the creamed mixture, beating well after each addition, then mix in the vanilla extract.
05 -
Alternately add the dry ingredients and buttermilk to the wet mixture, beginning and ending with the dry ingredients. Mix until just combined.
06 -
In a small bowl, mix the brown sugar and cinnamon thoroughly. Set aside.
07 -
Spoon a portion of batter into each lined cupcake cup, then add a spoonful of the cinnamon sugar filling and optional nuts. Top with remaining batter to cover the filling.
08 -
Bake in the preheated oven for 18 to 20 minutes or until a toothpick inserted into the center comes out clean. Remove from oven and cool completely.
09 -
Beat softened cream cheese and butter until smooth. Gradually add powdered sugar and vanilla extract, mixing well.
10 -
Add milk gradually, stirring until the frosting reaches the desired consistency for spreading.
11 -
Spread the prepared frosting evenly over cooled cupcakes before serving.