Preheat oven to 350°F (175°C). Coat a loaf pan with a piece of parchment paper.
Cream butter and sweetener in a large bowl till light and fluffy.
Add eggs in a separate dose swirling it after each addition. Add vanilla and extract of almond.
In another bowl, almond flour, coconut flour, baking powder, and salt should be mixed.
Add the dry ingredients in the wet mixture slowly and in turn with heavy cream.
Mix until smooth and creamy. Fold in lemon zest if using.
Pour batter in the prepared loaf pan and level off the top.
Bake 45-50 minutes or until tooth pick inserted in center is clean.
Let it cool off, but leave it on the wire rack to cool fully.
Slice, cut, and consume your juicy, buttery and low-carb dessert!
Tips:
To add additional flavour, add lemon glaze, which is keto-friendly.
Keep leftovers in an airtight container of up to 5 days or freeze leftovers of up to 2 months.
None of the ingredients (eggs and butter in particular) should be cold, as this results in poor texture.