Skip to main content

How to Make Your Buttercream Completely Smooth on Your Cake

Fondant icing is popular because of its smooth and flawless finished look.  Unfortunately, the taste of fondant, especially the packaged kind, leaves something to be desired.  It was inevitable that buttercream frosting would make a comeback.  Can you get that same wonderful look that you have with fondant?  Yes.  How do you get the smooth and flawless look with buttercream icing?  Easy!  Follow the method below for smooth buttercream icing.

For buttercream recipes that are all butter OR ½ shortening and ½ butter this first method works best.

Tools Needed

  • Metal spatula
  • Cake Icing tip (optional)
  • Exacto knife
  • Spackling knife (from hardware store, but dedicated to cake decorating only)
  • Turn table (optional, but recommended)
  • Parchment paper


Turn the pan upside-down and trace onto whatever you are using for the cake board (foam core, cardboard, wood, etc).

Cover the outline with the parchment paper about 1 -2 inches larger than the pan’s outline.  Tape securely, making sure that there are not wrinkles.

Using your favorite buttercream frosting recipe with butter, ice the area of the circle ¼ inch thick, extending ¼ inch past the outline.  Place the cake board in the refrigerator for pure butter buttercream frosting, or the freezer for part shortening-based buttercream icing, until firm, approximately 10 – 15 minutes.

Once thoroughly chilled, take the cake board from the refrigerator/freezer and take the top cake layer and place in the center of the iced circle upside down, the top of cake should be touching icing circle.  Fill and add additional layers.  Remember to place the top layers of the cake before the bottom layers.

Lightly crumb coat the sides of the cake and chill a few minutes to set the buttercream so that crumbs do not get into your final coat of buttercream frosting.   

When the crumb coat is chilled, place the cake board with cake on the turntable.  Dip the spackling knife in HOT water and dry with a paper towel.  Using one hand and the spackling knife, apply the final coat of buttercream frosting to desired thickness by holding the blade against the side of the cake at a 45 degree angle, turning the cake and smoothing buttercream icing at the same time as application.

Be sure the spackling knife is touching the parchment paper or else there will be a line of icing pushed out under it!! 

Once buttercream icing is on cake to desired thickness, repeat without icing, rotating cake slowly, in one motion so that the spackling knife does not stop touching the cake.  Smooth any icing build up over onto the bottom (currently top) of the cake with a small spatula.  Repeat until sides are smooth.  If any icing has come under the blade while doing this step, simply push away. 

Once you are happy with the smoothness, carefully cut the parchment paper loose from the board ALL THE WAY AROUND THE CAKE using an exacto knife.  DO NOT remove the parchment paper.  Carefully return the cake to the refrigerator/freezer for 10 – 15 minutes. 


Prepare the serving cake board by smearing some buttercream frosting on it.  Remove the cake from the refrigerator/freezer, center on serving board and quickly flip the cake over.  Remove the cardboard, but leave the parchment paper.  Return to refrigerator/freezer for 10 minutes. 

Remove the parchment paper carefully.  Cake should be perfectly smooth with crisp, clean edges.   

Suggested buttercream frosting recipe:


  • 3 sticks butter at room temperature
  • 1 cup shortening (avoid transfat free shortenings)
  • 2 pounds powder sugar
  • 1 tablespoon clear vanilla


  • Mix butter and shortening until well blended
  • Add sugar all at once and mix on low.  Mixture will be dry, but become smooth as it mixes.
  • If too stiff, heat a few tablespoons milk in the microwave until very HOT and add to mix one tablespoon at a time until smooth.
  • Add vanilla
Scroll to Continue

For shortening-based buttercream recipes this second method works best.  It is highly recommended that you use a crusting buttercream recipe.

Tools Needed

  • 2” high-density foam roller (for sheet cakes and shaped pans)
  • 6” high-density foam roller (for all other cakes)
  • Metal spatula
  • Cake Icing tip (optional)
  • Viva paper towel


Frost cake as you normally would, including crumb coating.  If you are unfamiliar with icing cakes, start with the above method until you start using the spackling knife without buttercream frosting.  Smooth icing lightly; it’s not meant to be perfect at this point.

Allow to fully crust.  This takes about 15 minutes; in high-humidity, it can take up to 30 minutes.  If you have used a non-crusting buttercream icing, refrigerate until icing sets.

Take the foam roller and gently roll across the top of the cake.   

NOTE: It is very important that the paint roller is a high-density foam roller or it will not smooth the cake properly.Use long, light and gentle strokes across the surface. Do not use short or fast strokes, as this may shift icing. 

Continue to gently roll the high-density foam roller across the cake until there are no bumps, wrinkles or air pockets.  Repeat with sides of cake once top is done.  Be sure to fully hit sides of cake from top to bottom in single strokes.

Touch up top and sides using Viva paper towel between roller and cake for a finer finish.  Viva brand has no patterning to the paper towel for a smooth finish.  Parchment paper can be substituted for Viva paper towel.


Icing pulls away from cake and sticks to roller head:   Either (1) buttercream icing is not crusted well enough.  Allow more time to crust (refrigerate if using non-crusting icing) OR  (2)You are using short, jerky strokes. Use longer, slow and smooth strokes to gently manipulate icing.

Icing cracks and looks dry when I roll it: Icing is too crusted. Reapply a thin layer of icing and roll before it becomes too dry.

Air holes are not disappearing when I roll: Use a slightly firmer pressure. While you do not want to push down the icing, you do want to push firmly enough to smooth out air bubbles and holes.

Roller Care

Wash roller foam pad will with dish soap and hot water before first use and immediately following subsequent uses.  Rinse thoroughly, use fingers to remove excess water. 

For easiest cleaning, do not apply soap directly to foam.  Lather dish soap in your hands, and then use your hands to wash foam.

Allow foam to completely dry before using.  It is recommended that you do this at least 1 – 2 days in advance.  Roller must be absolutely dry before using this method.

It is recommended to have roller refill heads available in case the foam becomes wet or damaged in the middle of smoothing your cake. 

Foam roller may become stained from colored buttercream icings, but it will not affect use.  Color stains should not bleed onto a white cake during consecutive uses, if washed well.  If unsure, test by rolling some icing on a sheet of waxed paper before using on cake.

Suggested Sharon's SugarShack Crusting Buttercream icing recipe:


  • 5 generous cups of shortening
  • 5 pounds of powdered sugar
  • 4 TBSP of flavoring
  • 11-12 TBSP Hot coffee creamer liquid. (Use powdered and mix 11-12 tbsp of powder to 11-12 tbsp of hot water---almost boiling)


  • Cream shortening, flavoring and hot liquid with paddle attachment until well combined and creamy.
  • Then stream in first 3 pounds of powdered sugar with mixer running at speed one.
  • When incorporated somewhat stop and scrap down sides of bowl well.
  • Stream in last 2 pounds of sugar at speed one.
  • When incorporated turn the mixer up to speed 6 and let it beat 5-7 min. until very smooth. Scrape down the sides of the bowl very frequently while the mixer is going at speed 6. Cool before using

With practice, these methods will make your buttercream frosted cakes look as smooth as fondant, but taste much better.


EnteniaGede on March 06, 2013:

My partner and i accustomed to get at the top of living however of late We have built up a new level of resistance.

Related Articles