To fill: spread the dulce de leche on top of cake and place the second cake on top (if cakes are domed, level with knife before filling). (cookingwithbooks.net)
Spread raspberry filling over the cake, leaving about 1 inch around the edge so it doesn't spill out the side when you put the second cake on top. (greensnchocolate.com)
Carefully add the second cake on top of the first. (azgrabaplate.com)