Learn how to make this amazing 3D Geometric Cake by Kenya Brooks at the Yellow Cake Company!
To begin you will need:
- A rolling pin
- Cornstarch and/or powdered sugar for rolling
- Pastry cutter
- A veining tool
- Clear ruler or straight edge
- A square pan
- Gumpaste in desired colors
- A luster dust or highlighter in desired color (gold highlighter shown here)
- A clear alcohol or lemon extract
- A fan brush
- A piping bag with a round tip (wilton #5 shown here)
- Basic buttercream (either butter or shortening base is fine) or royal icing. If using a royal icing be sure to keep it a thick consistency.
- And don’t forget the cake! This technique can be done on either a buttercream or fondant cake (smooth buttercream is shown).
Powder your work surface with either cornstarch or powdered sugar. Roll out the gumpaste to about 1/16” thickness. Use your straight edge and veining tool to lightly score a line into the gumpaste. Be sure not to cut it. You just want to make an indentation. This will give you a center line and also help to make a clean bend in the pieces when drying. For this next part you can either “eyeball” it or use pre-cut patterns from parchment paper. Start from your center line. With your pastry cutter from the top cut an angle away from that line. Mirror that angle on the other side. Then from the bottom cut another angle up to meet your first cut. Repeat on the opposite side to make a diamond. Tip: Once you have cut the first 3 lines lay your straight edge perpendicular to your center line. At the intersection of the straight edge and your top angle make a small mark. Then you can just line your straight edge up with that mark and bottom point of the diamond and make your final cut so that your piece is symmetrical. Don't try to fold the piece in half and cut the opposite side. You want to handle each piece as little as possible to keep the edges straight and smooth to ensure you get a clean look in the end.
Take your square pan and lightly dust with cornstarch. Place your cut piece in the pan making sure to keep the bend straight and sides flush against the side and bottom of the pan. Let dry for at least 2 days. Drying time may vary depending on your climate.
Once your pieces are completely dry take some time to arrange them on your work surface so you can make a preliminary plan before arranging them on the cake. This will save you some time and ensure that your arrangement is exactly what you want.
Now it is time to select a few pieces to brush with a highlighter or luster dust. This of course can be in any color, metallic, glitter, anything! Mix a small amount of dust with a clear alcohol or lemon extract. Be careful not to add too much liquid. I use an eyedropper to better control the ratio. Dip the fan brush and dab off the excess. Lightly brush the sides of your piece and set aside to dry.
Prepare your piping bag with round tip and either buttercream or royal icing. Take your first piece and pipe along the bottom edges and corner. Start at the top and firmly press the piece onto your cake. Rinse and repeat.
From here it is a puzzle as to how all the pieces fit together. This is why it is good to make a plan before placing on the cake. There is really no wrong way to do this. Just keep placing until your happy with the arrangement.