A delicious low carb almond flour cake with sugar-free vanilla pastry cream and a rich sugar-free chocolate ganache frosting.
I have lived in the Boston area for over 8 years. It’s longer than I ever lived in Phoenix or Vancouver, and it seems likely that my time here will come to surpass even the time I spent in the city of my childhood, Toronto. This surprises me somehow, that a city I knew little of or ever really cared about growing up is the city where I appear to have put down roots. The husband/kids/house kind of roots. Those aren’t the sort of roots that are easily transplanted on a whim. There is much to love about this area, such as the history and the culture that is visible almost everywhere. These things are part of the reason we chose to move here. There is also much about the area that frustrates me, such as the crazy driving and the lack of street signs. I often make my way to a destination more by feel than by proper directions. And try giving driving directions to an outsider! I always feel awful, wondering if I’ve sent the poor sucker on a wild goose chase.
One little bit of Boston culture that I hadn’t experienced until now is Boston Cream Pie, which according to Wikipedia is the city’s “official dessert”. And in keeping with the Bostonian way of making things confusing, it isn’t a pie at all, but really a cake. A cake filled with vanilla pastry cream and topped with chocolate. Okay, so they might be out to confuse outsiders with improper names and signage, but when it comes to dessert, Bostonians aren’t messing around! You can’t really go wrong with a cream-filled cake topped with luscious chocolate ganache. Now that I’ve made one and tasted it, it seems astonishing I never did this before.
And I probably never would have tried it, if it hadn’t been a special request by a reader. Here’s the problem, though – I can’t figure out who requested it. I know someone did, because I remember thinking it was a great idea and wondering why I didn’t think of it on my own. But when I look back over the comment fields of the posts where I opened my blog up to requests, I can’t find it at all. So if YOU were the person who urged me to try my hand at a low carb, gluten free Boston Cream Pie, speak up! I want to thank you. As it turns out, this was a fairly easy dessert to render low carb. I knew instantly that I would use my cake recipe from the Lemon Cream Cake, and in fact, I actually used the layer I had frozen when I decided that the Lemon Cake was going to be too big. This was my first time making pastry cream, but I’ve made plenty of other custardy things before so I was confident in my ability. After that, it just needed a thick, chocolatey, ganache type topping and I’ve certainly made plenty of those for this blog!
The Results: I think I hardly need to tell you that this was good – the chocolate dripping down the sides in the pictures should be proof enough. I was delighted by how the cake layer I’d had in the freezer thawed out, and cut nicely into two layers. The pastry cream was easy to make and tasted so good that I deliberately left a little in the bowl to eat separately from the cake. I will confess that in my impatience, I didn’t leave the pastry cream to set in the fridge long enough, so it did squish out a bit from the sides of the cake, but I kind of liked the way it looked, all ooey and gooey. Unlike some of my low carb creations, this cake was a hit with every single member of the family. In fact, I received multiple thanks from the kids for this one!
In this recipe, I used Safest Choice pasteurized eggs for the pastry cream. These are eggs that have been pasteurized in their shell and I like to use them when I know the kids will be eating my creations. The yolks in the pastry cream technically do get “cooked” from the heat of the cream, but it makes me feel a little bit safer when I know my littlest one will be tasting it.
Boston Cream Pie
Pastry Cream: (make this first and let it chill while making the other parts)
1 1/4 cups whipping cream
3 egg yolks
1/4 cup granulated erythritol
1 tbsp cornstarch
2 tbsp butter, cut into two pieces
1 1/2 tsp vanilla extract
16 drops stevia extract
2 cups almond flour
1/4 cup granulated erythritol
1/4 cup whey protein powder
1 tsp xanthan gum
2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
6 oz greek yogurt
1/4 cup butter, softened
3 large eggs
1/2 tsp vanilla extract
10 drops stevia extract
1/4 cup almond milk
5 tbsp butter
2 oz unsweetened chocolate, chopped
2 tbsp powdered erythritol or xylitol
1/4 cup cocoa powder
1/4 tsp vanilla extract
16 drops stevia extract
For the pastry cream, bring whipping cream to a simmer in a medium saucepan over medium heat. In a medium bowl, whisk egg yolks with erythritol and salt, then whisk in cornstarch until mixture becomes pale yellow and thick, about 30 seconds.
Slowly whisk about half of the hot cream into the yolks to temper, then return the yolk/cream mixture back to the saucepan and cook until thick and glossy, about 1 1/2 minutes, whisking continuously. It thickens up suddenly and quickly, so watch carefully!
Remove from heat and whisk in butter, vanilla and stevia. Transfer to a small bowl and press plastic wrap flush to the surface. Chill in refrigerator at least 3 hours.
For the cake, preheat the oven to 350F and grease an 8-inch or 9-inch round cake pan.
In a medium bowl, whisk together the almond flour, erythritol, xanthan gum, protein powder, baking powder, baking soda and salt, breaking up any clumps with the back of a fork. Set aside.
In a large bowl, beat yogurt and butter together until smooth. Add eggs, vanilla and stevia and beat until just combined. Add half of almond flour mixture and beat until combined, then beat in almond milk. Beat in remaining flour mixture until thoroughly combined.
Spread batter in prepared pan and bake 35 to 40 minutes or until edges are golden brown and a tester inserted in the center comes out clean. Cool in the pan 10 minutes and then flip out onto a wire rack to cool completely. When cake is completely cool, cut in half horizontally with a serrated knife.
For the chocolate glaze, melt butter, chocolate and powdered erythritol together in a small saucepan over low heat. Stir in cocoa powder, vanilla and stevia and whisk until smooth. Remove from heat and let sit 5 to 10 minutes, while assembling cake, until glaze is thicker but still pourable.
To assemble, separate the two halves of the cake. Place the bottom half cut-side up on serving dish and spread with pastry cream. Gently top with the second half, cut-side down and lining the edges up carefully. Pour chocolate glaze over the top of the cake and spread with a knife or offset spatula, pushing to the edges and letting it drip down over the sides.
Let glaze set 1 hour before serving.
Serves 10. Each serving has a total of 10.2 g of carbs and 4.3 g of fiber. Total NET CARBS = 5.9 g.