Allergy-friendly Nanaimo Bars

This is modified from the original recipe at hiddenponies, which is also excellent if you don't have any food allergies. Because real butter is amazing, I think the original tastes slightly richer, but nobody who tried my version even guessed they were gluten, dairy, egg, and soy-free.

Ingredients

BASE:
¾ cup vegan butter substitute (I use Melt, as it is also soy-free; note that some vegan butters are NOT soy free)
¼ cup sugar

6 tbsp cocoa powder
1 tsp vanilla extract

¼ cup organic apple sauce

½ cup almond flour

½ cup coconut flour or oat flour

1 cup ground or finely chopped walnuts
1 cup unsweetened shredded coconut

MIDDLE LAYER:
½ cup vegan butter or margarine, at room temperature (leave out a few hours in advance)
6 tbsp rum or other gluten-safe alcohol (or almond milk/lactose free milk for non-alcoholic version)

1 tsp vanilla extract
4 cups icing sugar (aka powdered sugar or confectioner's sugar)

TOP LAYER:
8 oz soy free semi-sweet or dark chocolate (this can be hard to find! See instructions below.)
1 tbsp vegan butter

Instructions

1. BASE: Combine first 4 ingredients in large saucepan. Heat and stir over medium-low heat until mixture is smooth. Remove from heat.
2. Stir in the remaining base ingredients. Pack firmly into ungreased 9x13” pan, pressing down and smoothing the top. Chill in fridge/freezer while you prepare the middle layer.
3. MIDDLE LAYER: Beat the butter and vanilla together then slowly mix in the sugar and rum. If it becomes too stiff to mix, add a little more rum, but don't let it get too soft or the finished bars will melt at room temperature. Spread over first layer and smooth the top. Chill for 45 minutes in freezer.
4. TOP LAYER: 
1. Ideally, find soy-free dark chocolate (you need to avoid soy lecithin, which is in almost all chocolates - I found Green & Black 80% dark chocolate is soy-free, but almost nothing else easily available), then simply melt chocolate and butter in a small bowl at 50% power in microwave. Microwave for about 1 minutes, stir and microwave another 30 seconds or longer if needed, stirring frequently. Melt as slowly as possible - overheated chocolate will develop a coarse texture and be hard to spread.
2. If you were NOT able to find soy-free dark chocolate, probably the next best thing is dark baker's chocolate. Several brands of this do not contain soy lecithin, but they also do not contain sugar so are extremely bitter. You'll need to melt this slowly over a pan of warm (but not boiling) water to avoid it getting overheated too fast and becoming coarse. Add icing sugar slowly, mixing in thoroughly. You'll probably need between ½ to 1 cup of icing sugar to sweeten it enough to not be bitter.This is difficult to get right and I highly recommend option 1 if at all possible.

Remove the pan from the freezer and spread the chocolate topping quickly and evenly over middle layer. Smooth the top. Because the icing below is frozen, it will start to harden fast, so move quickly. Once the chocolate is starting to harden, take a sharp knife and cut the bars. Return to fridge until ready to serve.

Note: this can be a difficult recipe to make, mainly because of the chocolate layer. Overheating chocolate will ruin it, and avoiding this can be very touchy. If you've never tried melting chocolate before you may want to experiment with a smaller amount in advance. If you do overheat it, it will still be edible, it just won't have as smooth a texture and it will be harder to spread.