Extra virgin olive oil can most likely be substituted for the butter. Filippo Berio recommends a substitution of ¾ cup olive oil for 1 cup of butter. (See Filippo Berio substitution chart here in this PDF.
) I love baking with olive oil when I can; it adds richness and moisture to gluten-free baked goods. (Along those lines, you may also be interested in my Perfect Pound Cake
recipe, which uses olive oil.) Liquefied coconut oil would also likely be a good substitution for the butter. I tend to use less coconut oil than is called for when substituting coconut oil for butter.
A cup of coconut/palm sugar (total amount) can be used in place of both the granulated sugar and brown sugar. Sifted coconut flour instead of gluten-free all-purpose flour should work in this recipe,too, as it works fine in my crustless pie recipes, like my Best Ever Pumpkin Pie
Because this pie will come out very thin if you use a standard (not deep dish) 9-inch pie plate, making this recipe an opportunity to use a smaller pie plate that you don’t often get to use. Baking in a smaller pie plate will produce thicker slices; baking time may have to be adjusted slightly. However, using a standard 9-inch pie plate is perfectly acceptable. With any size pie plate, this pie will yield more servings than most pies due to its rich flavor.
If you’d like to make this pie with a crust, reduce the gluten-free flour mix to ¼ cup and pour all into an unbaked pie crust. My No Roll, Never Fail, Press-In Pie Crust
is a good, easy option for a pie crust for this fudge pie.
Adding nuts can be a great (and more nutritious) option for those who can indulge in them, but I find that I prefer this pie without nuts most often. I don’t like nuts in my fudge and adding nuts to this pie makes it more of a brownie pie than a fudge pie in my opinion. When I do add nuts (usually walnuts) per request, I tend to prefer the crusted version to balance the slightly more substantial filling. All in all, I prefer the crustless version without nuts for the ultimate in chocolate flavor.