For the filling - Beat the cream cheese and lemon rind together on medium-high speed using a hand beater or stand mixer for 2 minutes or until smooth. Add in the passionfruit, condensed milk, lemon juice and salt, then beat for a minute. Cover the filling mixture with plastic film and let it chill in the fridge for 30 minutes.
For the whipped cream - Place cream, vanilla extract and icing sugar in a large bowl and whip on high speed using a hand or stand mixer. Whip the cream until it reaches stiff peaks. Once you lift the whisk, the cream peaks should stand upright.
On a long serving plate (approx. 40cm/16in in length), spread 1/2 cup of whipped cream in the centre of the plate lengthways. Doing this will help hold the biscuits up. Cover the remaining cream with plastic film and chill in the fridge until needed.
In a small bowl, combine the orange juice and brandy (if using). Quickly dip a biscuit, then place 1 tbsp of filling on the flat side of the biscuit and place it upright on the cream. Do the same for the second biscuit, then stand it next to the first biscuit and press it gently together. Repeat this same process with the remaining biscuits until it forms a log.
Spread the whipped cream on the top and sides of the biscuit log, covering it completely. Place the plate and the log in a large sealed container or cover it loosely with plastic film. Leave to chill for at least one night or up to 3 days ahead before serving.
Garnish the log with passionfruit pulp and mint sprigs. Cut the cake diagonally so the biscuits inside look pretty when serving.
Notes
(NOTE 1) Gingernut biscuits are very hard cookies that are usually dunked in hot drinks before consumption. They have a lovely ginger and slightly caramel taste. You could sway gingernut biscuits with any round and plain (no filling) ginger-flavoured cookies. You could also use vanilla, butternut or chocolate-flavoured cookies instead.(NOTE 2 )Thickened cream (whipping cream) has gelatine added to it and contains 35% milk fat. I don’t recommend using low-fat cream because it may not whip up well and be a little runny. We need to whip the cream to firm peaks so it'll hold its shape.(NOTE 3) Icing sugar (powdered sugar, confectionary sugar) - Icing sugar usually comes in two forms: icing sugar mixture and pure icing sugar. Icing sugar mixture is softer than pure icing sugar because there's starch or flour added to it. For this recipe, I used the icing sugar mixture as the cornstarch helps stabilise the cream.Leftovers - Transfer the Christmas Log into a sealed container and store it in the fridge for up to 4 to 5 days, depending on fresh your thickened cream is.I've used a third-party application to calculate the calories and nutritional information, so please use this as an approximate guide only.Cooking measurements are in Australian standard spoon and cup measurements. For specific details and conversions, visit ourAustralian Cooking Measurements page.