When filling and icing a cake with a buttercream frosting, the challenge is to prevent crumbs from catching in the icing.

To help frosting spread more smoothly, get rid of loose crumbs with a pastry brush.

Cold icing is difficult to spread and pulls on the surface of the cake, so if you’ve made the icing ahead and chilled it, give it ample time to warm and soften.

Also, placing the cake’s sturdy bottom crust face-up on the top layer minimizes crumbs and provides distinct, clean edges that are easy to ice.

Spreading a thin coating of frosting on the sides helps seal in any crumbs, allowing for a smoother overall look.

Finally, applying a base coat, or “crumb coat,” of icing seals in loose crumbs so that they do not mar the cake’s appearance.

To anchor the cake, spread a dab of frosting in the center of a cardboard round cut slightly larger than the cake. Center the upper layer of a split cake crust-side up or one cake of separately baked layers bottom-side up on the cardboard round.

Spread a dab of frosting on the center of the cake stand, then set the cardboard round with the cake on the stand.

Place a large blob in the center of the cake and spread it to the edges with an icing spatula. Imagine that you are pushing the filling into place rather than scraping it on as if it were peanut butter on a slice of toast.

Don’t worry if crumbs are visible in the icing; since the filling will be sandwiched between layers, these crumbs will not be noticeable.

To level the icing and remove any excess, hold the spatula at a 45 degree angle to the cake and, if using a rotating cake stand, turn the cake.

If you’re not using a rotating stand, hold the spatula at the same angle, and, starting at the edge farthest away from you, gently drag the spatula toward you. It will take a few sweeps to level the icing.

Using a second cardboard round, slide the top cake layer crust-side up on top of the frosted bottom layer, making sure that the layers are aligned.

Press the cake firmly into place.

A thin base coat of icing helps seal in crumbs. To coat the top, place a blob of icing in the center of the cake and spread it out to the edges, letting any excess hang over the edge. Don’t worry if it is imperfect.

Scoop up a large dab of icing on the spatula’s tip: Holding the spatula perpendicular to the cake spread the icing on the side of the cake with short side-to-side strokes.

Repeat until the entire side is covered with a thin coating.

Refrigerate the cake until the icing sets, about 10 minutes.

Apply a final thick coat of icing to the top and the sides, following the steps above, making sure that the coat is even and smooth.

When icing the sides, apply a coat thick enough to cover and conceal the cardboard round. Dipping the spatula into hot water will help create a smooth coat.

As you ice the top and sides, a ridge will form along the edge where they meet.

After you’ve finished icing, hold the spatula at an angle, and, with a very light hand, starting at the farthest edge of the cake, smooth the ridge toward the center. Rotate the cake and repeat until the ridge no longer exists.

If you have any tips on icing a cake, please post your comments below.