At first you need a number of pieces, 8 (or 16) is the easiest solution because you get the angle by folding a paper twice (or three times). Use you constructed or caclulated angle to build your basic area (equilateral triangle, here 18cm both sides) of a draft. Choose a cake height (here 7cm) and apply it to the basement. Afterwards to the same with a bit larger triangle (18,5cm sides, 3cm edge) for the roof. So you have an impression of the size.
Now copy your model to a (robust) paper of your choice. I used colored printing paper and this was not a good idea because the wall could barely hold the candy. In the images you can see that my model is a bit to large for a normal sheet of paper. I fixed the missing part later and i think it's a good compromise. Oh and before you glue it: be sure to have prefolded all the edges or it will be a mess.
Afterwards to the same with the roof pieces, don't forget to cut a nice fluend cream :D
Now comes the decoration. For the sides i tried to use self-adhesive papers (labels) because otherwise you will have to be super precise with your glue or the roof will get stuck between the papers. Also apply the decoration in the lower part of the sides, the top will not be seen.
For the top just be creative. I used felt pads as cream and chocolate dots. I had leftover gift band which would have been also nice as side decoration.