Lovely low carb Boston Cream Pie (cake)

Made this yesterday, was really good.
I used coconut flour and stevia mix for the cake and stevia mix for the custard to go in the middle, with 85% chocolate for the ganache. It worked really well, very little effect on bs at the time or overnight. It was moist and DH said it was in line with the original recipe. If anyone wants the recipe I will post.
Could also be used for jam and coconut sponge and custard for dessert.

Cake (I made two to sandwich together). You'd probably only need one for a dessert.
50g coconut flour (I used one from Tesco, I think they may vary slightly in density so you might have to experiment).
6 large eggs separated
2 tbsp HalfSpoon white granulated
1 rounded tsp baking powder
2 tbsp water (can add a bit more if mixture too stiff)
1 tsp vanilla essence

Preheat oven to 180 deg.
Pre-line 8" baking tin so it's ready to be used straight away.
Sift together flour and baking powder.
Add egg yolks, halfspoon, vanilla essence and 2 tbsp water. I whisked them with an electric mixer till well combined and consistency of medium batter.
Whisk egg whites till stiff and gently fold into mixture, make sure it's well incorporated so not eggy, but don't knock out the air.
Pour into tin and bake for 35 mins.

Custard for middle: you could use this hot for dessert.
4 medium egg yolks
2 oz half spoon (could use less or sweetener).
1 tsp vanilla extract
1 oz cornflour
500 ml of whole milk

Whisk egg yolks, half spoon and vanilla essence together in a large bowl, then whisk in cornflour.
In medium pan bring milk to the boil, whisk it onto the egg mixture then return to pan and cook over medium heat, stirring constantly to give a thick smooth custard. Pour through sieve into large bowl, cover with cling film and leave to cool.

Glaze
100 g dark chocolate (70%+ coco solids)
100 ml dbl cream

Break up dark chocolate and place in small bowl. Bring cream to the boil in small pan and pour over the chocolate.leave for 2 mins, stir until combined into smooth glaze.

When custard is set and cakes are cool spread custard over cake and sandwich together. Smooth glaze over the top letting some trickle down over sides.

Should keep for a couple of days in the fridge loosely covered, remove 30 mins before eating.

I had no problems with this, made it twice. I think the secret is in incorporating eggs properly and getting into the oven quickly . Hope it works well for you.

The cake put my bs up by 1.3 mml, not too bad for a piece of cake I thought. I dont know if it would set without cornflour? You don't get much of the custard in a slice. Maybe dilute with cream?

I have researched, and think you can use almond milk for custard. I might try that instead.