Preheat oven to 350 F. Combine the flour, baking powder, baking soda, salt and spices in a small bowl, and whisk them together. Set aside for a moment.
Place the butter and both sugars in the bowl of a stand mixer fitted with a paddle attachment. Beat on medium speed until light and fluffy, about 3 minutes. Add the eggs one at a time, beating well after each addition, then add the vanilla extract.
Turn the mixer speed to low and add about a third of the dry ingredients. Once the dry ingredients are incorporated, add half of the buttermilk and mix it in. Add half the remaining drys, then the rest of the buttermilk, and finish with the remaining dry ingredients. Stop the mixer when just a few streaks of flour remain. Finish mixing by hand with a rubber spatula, scraping the bottom and sides of the mixing bowl well. Stir in the cinnamon chips, if using.
Scoop the batter into 18 cupcake liners. Bake for 20 minutes at 350 F, until the tops spring back lightly when touched. Cool completely.
To Make the Almond Buttercream:
Put the butter, powdered sugar, 2 tbsp milk, vanilla extract, 1/2 tsp almond extract, and salt in the bowl of a stand mixer fitted with a paddle attachment. Beat the mixture on low speed until the dry ingredients are incorporated. Raise the speed to medium and beat for about 2 minutes, until light and fluffy.Taste the buttercream, and add additional almond extract if you would like a stronger almond flavor. If the frosting is very stiff, add small amounts of milk until it is the consistency you want. Add 2 drops of pink food coloring and 1 drop of ivory, and mix them in. Add more food coloring as necessary to get a color you like. Almond Buttercream can be made in advance and stored in the refrigerator for up to a week. If you have made it in advance, let it come to room temperature and re-beat until light and fluffy before using.
To Decorate the Cupcakes with Brains:
Place the buttercream in a piping bag fitted with a round tip about 1/4-inch wide: a Wilton #10 tip or Ateco #12 tip will work well. Pipe a thin layer of buttercream on top of the cupcakes, and smooth it out with a knife or offset spatula. It doesn’t need to be perfect, it’s just going to be the base of the brains.Pipe a line down the middle of a cupcake, then fill up the space to the right with one long buttercream squiggle, beginning at the top, widening through the middle, and narrowing at the bottom. Repeat on the left side, until you have formed both halves of the “brain.” Repeat until all of the cupcakes are decorated with brains.