Preheat your oven to 350°F (175°C).
In a large mixing bowl, beat the 8 large eggs until light and frothy. Gradually add in melted coconut oil, vanilla extract, and allulose. Mix until well combined.
In a separate bowl, whisk together almond flour and baking powder. Slowly add dry ingredients to wet mixture, stirring until just combined.
Divide the batter between two 9-inch round cake pans and bake for 25-30 minutes, or until a toothpick inserted comes out clean.
Allow cakes to cool in the pans for 10 minutes before transferring to a wire rack to cool completely.
While the cake layers are cooling, prepare your keto custard according to your favorite recipe.
Once cool, place one layer on a serving plate. Spread the keto custard evenly over the top and place the second layer on top.
Spread keto frosting over the top of the second layer generously.
Chill the assembled Keto Boston Cream Pie in the refrigerator for at least an hour before slicing.