Welcome to the Cake Decorators Q&A

I am making an engagement cake and have prepared silhouette figures of the happy couple and wonder what is the best way to secure them to the top of the cake.
many thanks

Hi Canada1

There are several ways of standing cutout figures on top of a cake. It depends on how big, thick and tall the figure is.
I use tempered/melted chocolate to stick down cut out figures. Temper/melt a small amount of dark chocolate in the microwave and add black colour to darken it more (in the case of black silhouttes) Let the chocolate thicken, place a spoonful in a parchment bag and pipe a thin line as glue for the figure to stand on, use cool spray to ensure total adhesion or hold the figure in place until set. If the chocolate is tempered it will set within a few seconds.
If the figures are quite big and thick insert cocktail sticks in the legs/leg before the gumpaste dries. Dry the figure and insert into cake. See how Paul does it in this tutorial:

Cartoon Pig Cake

Hopefully other members will share tips.

Flat figures can be stuck on the side of cakes with a little edible glue, cooled boiled water, piping gel or a little shortening.