by KetoDietApp.com
Step 1Preheat the oven to 160 °C/ 320 °F (fan assisted), or 180 °C/ 355 °F (conventional). (To make this recipe dairy-free, check the tips in the post above.)
Step 2Separate the egg whites from the egg yolks. Place the egg yolks, vanilla, rum and sweetener in a mixing bowl and beat with an electric whisk until pale, about 2 minutes.
Step 3In a clean mixing bowl, whisk the egg whites (adding the cream of tartar as they start to foam) until stiff peaks form. If you don't have cream of tartar, use an equivalent amount of apple cider vinegar.
Step 4In a third mixing bowl, mix the dry ingredients together (almond flour, cacao, psyllium husk powder, baking soda and salt).
Step 5Fold into the egg yolk mix and the rum with a spatula. This will be dry, don’t worry.
Step 6Fold through the eggs whites. This will get hard so use an electric whisk towards the end but for just long enough for it all to combine and the batter is smooth. Don’t over-beat the batter or you will deflate all the eggs.
Step 7Pour the mix into a greaseproof lined baking tray or sheet pan (25 x 38 cm/ 10 x 15").
Step 8Bake for 10 - 12 minutes until just set. Don’t over bake or the sponge will be too dry to roll. Remove from the oven and allow to cool for 2 minutes.
Step 9Flip onto a clean sheet of baking paper and cover with a damp towel. (Not wet, just damp enough to loosen the baked on baking paper). Allow to cool for 2 more minutes and peel off the baking paper.
Step 10Whilst warm, tightly roll the sponge away from you (lengthways) with the parchment paper. Cover with a clean tea towel to cool whilst you prepare the filling.
Step 11To make the filling whisk the cream until the mixture is just under soft peaks. Fold through the mascarpone and optional sweetener.
Step 12Unroll the sponge, making sure the parchment is underneath. Spread over the filling leaving 2 - 3 cm/ 0.5 - 1" at the edges for over spill of the filling as you roll.
Step 13Carefully roll up once more making sure the join is under the bottom. Place in the fridge to chill on a greaseproof lined baking tray for 30 minutes whilst you prepare the ganache.
Step 14To prepare the chocolate ganache heat the cream till hot (not boiling). Add the dark chocolate and allow to rest for 5 minutes. Do not stir. When the time is up fold with a spatula until combined.
Step 15Tip: If your ganache splits, simply transfer to a food processor and pulse until smooth. A dash of warm water can also help making your ganache silky smooth again.
Step 16Once the chocolate log is chilled, cover with chocolate ganache using a spatula (make sure you cover the ends too). Place back in the fridge for 20 minutes, or until fully set.
Step 17Take a fork and create bark marks on the ganache. Optionally, dust with powdered low-carb sweetener and decorate with red currants or berries of choice.
Step 18Slice and serve!
Step 19Store in the fridge for up to 5 days or freezer for up to 2 months.