Frosting a Layer Cake

Basic cake tools...pans, cake decorating stand, piping bags, offset spatula, parchment paper, long bread knife.
Line your pans with parchment or waxed paper.
Bake your cakes and allow them to cool on a rack. Slice off any rounded tops.
Put on stand with parchment under. Put a bit of icing in the middle to keep the cake from moving around. Pipe around the layer and add filling (if desired). Add top layer. Apply crumb coat. Chill and allow to dry. Apply another coat on top and sides. Decorate with piping bag and tips if desired.

BUTTERCREAM FROSTING

1/2 cup unsalted butter, at room temperature 
2 cups confectioners' sugar, sifted
1 1/2 teaspoons pure vanilla extract
2 tablespoons milk
3 drops food coloring, or as needed (optional)

Cream butter in the bowl of a stand mixer fitted with the paddle attachment until smooth and fluffy.
Gradually beat in confectioners sugar until fully incorporated.
Beat in vanilla extract.
Add food coloring, if using, and beat for 30 seconds until smooth or until desired color is reached.
Use immediately or store in an airtight container in a cool, dark place for up to one day; for longer storage, refrigerate buttercream in a covered container, then bring back to room temperature before using. Use within 3 to 4 days.