30-Minute Keto Blackberry Hazelnut Semifreddo
This creamy frozen dessert combines rich egg custard with whipped cream, studded with fresh blackberries and toasted hazelnuts. The semifreddo has a silky, mousse-like texture that's softer than ice cream but firmer than pudding. Made with keto-friendly sweeteners like BochaSweet and Swerve, it delivers indulgent flavor without the carbs. Perfect for special occasions or when you want an elegant make-ahead dessert that serves a crowd. The contrast of tart berries and nutty hazelnuts creates a sophisticated flavor profile.
Ingredients
- 4 large egg yolks
- 1 large egg
- ¼ cup BochaSweet, (or allulose)erythritol1:1keto
similar sweetness
- 1 ⅓ cup whipping cream
- ¼ cup powdered Swerve Sweetener
- 1 tsp hazelnut extract, (or vanilla extract)vanilla extract1:1flavortree_nuts-free
mentioned in recipe
- 1 cup blackberries, divided
- ¾ cup toasted chopped hazelnuts, divided
Instructions
- 1
Grease a 9x5 inch loaf pan and line with two pieces of parchment paper so edges overhang the sides
- 2
Set a heatproof bowl over a pan of barely simmering water and add egg yolks, egg, and BochaSweet, whisking continuously until thickened
- 3
Remove bowl from heat and cool egg mixture to lukewarm, whisking frequently, then whisk in extract
- 4
Whip cream with powdered sweetener until stiff peaks form in a large bowl
- 5
Fold one large scoop of whipped cream into egg mixture to lighten, then gently fold egg mixture back into whipped cream until no streaks remain
- 6
Stir in blackberries and chopped hazelnuts, spread mixture in prepared loaf pan and freeze until firm
- 7
Run a spatula between pan and parchment paper, invert semifreddo onto serving platter and peel off parchment
- 8
Top with remaining blackberries and hazelnuts and cut into slices
Tips
Make sure the water is barely simmering when cooking the custard base to prevent the eggs from scrambling.
Cool the egg mixture completely before folding into whipped cream to maintain the light, airy texture.
Freeze overnight for best slicing results - a warm knife helps create clean cuts through the frozen dessert.
Good to Know
Keep frozen for up to 1 week tightly wrapped in plastic wrap
Must be made at least 8 hours ahead for proper freezing
Let sit 5 minutes at room temperature before slicing for easier cutting
Common Mistakes
Keep water at gentle simmer to avoid scrambling eggs
Cool custard completely before folding to prevent deflating cream
Substitutions
Nut-Free Alternatives
General Alternatives
FAQ
Can I use regular sugar instead of keto sweeteners?
Yes, replace both sweeteners with 1/4 cup granulated sugar and 2 tablespoons powdered sugar, but this will no longer be keto-friendly.
How long does this keep in the freezer?
Properly wrapped, the semifreddo stays fresh for up to one week. Cover tightly with plastic wrap to prevent freezer burn.
Can I make this without a double boiler?
Use a heavy-bottomed saucepan over very low heat, stirring constantly. Watch carefully to prevent eggs from scrambling.