Add the melted butter and water to the dry ingredients and mix slightly, then add sour cream mixture and mix until ingredients are well incorporated.
Pour about 1/4 cup batter into paper liners so they are about 2/3 full, then bake 18 -22 minutes or until a toothpick comes out clean in the center.
Let cupcakes cool in the pans for 5 minutes, then remove from pan and allow to cool completely on a wire cooling rack.
Cool completely before frosting.
Fire Buttercream
Beat butter until light and fluffy, then add powdered sugar and beat until smooth and a good piping consistency.
1 cup unsalted butter, 4 cups powdered sugar
Add the vanilla extract and milk, and beat until frosting is smooth and a good piping consistency.
2 tsp vanilla extract, 2 TBS milk
Divide the frosting equally into two separate bowls. Add orange food coloring to one bowl and red to the other. Mix each bowl until color is uniform throughout.
orange food coloring, red food coloring
Place orange frosting on one side of the piping bag and red frosting on the other side.
Garnish
Place a small dab of frosting in the center of each cupcake then break the pretzel sticks in half and arrange 6 pieces with broken end in the frosting and the other end pointing towards the outside edge of the cupcake like wood in a campfire.
1 bag pretzel sticks
Swirl the frosting over the end of the pretzels in the center of the cupcake to create the "fire."
Make the "toasting marshmallow" for the top by placing a mini marshmallow on the end of a pretzel stick then place the pretzel on top of the frosting "fire."
24 mini marshmallows
Notes
Be careful to split the frostings onto either side of the piping bags without mixing them up a lot or you’ll end up with whatever color red and orange together make, not the swirls you really want.Toast the mini marshmallows quickly with a kitchen torch if you really want to be gourmet and have “toasted” marshmallows on top of your cupcakes. I was too lazy to do that, but it’d be a fun touch!Store cupcakes in an airtight container of some kind for up to five days. No need to refrigerate since you’re using a buttercream frosting on these!