DIY Tim Tam slam

Instructions

1. Start with the ice cream. In a medium saucepan, heat the milk and cream to 40˚C over medium heat. While the milk is heating, in a separate bowl, combine the dextrose, milk powder, sugar and salt.
2. While continuously whisking, stream the dextrose mixture into the milk. Continue heating the mixture to 85˚C, stirring continuously to avoid any lumps forming, then remove from the heat.
3. Whisk the egg yolks in a medium bowl. Whisk in a splash of the hot milk mixture to temper the eggs, then, while whisking continuously, stream the egg yolks into the hot milk. Return to the heat and cook until the mixture reaches 85˚C, whisking continuously.
4. Remove from the heat, then stir through the chocolate. Use a stick blender to blend the chocolate into the custard, then strain through a fine mesh strainer into a heatproof bowl set over a larger bowl filled with ice water to help stop the cooking process. Allow to cool, then refrigerate for 4 hours at 4˚C. Place a silicone mould with 20 (5 cm x 3 cm) rectangular cavities into the freezer to chill.
5. Once chilled, use an ice-cream machine to churn the ice-cream, then spoon the ice-cream into each cavity of the silicone mould, filling all the way to the top. Use a palette knife to ensure the ice-cream is pressed into all four corners of the mould. Tap firmly on the counter to remove any air bubbles, then smooth the tops.
6. Cut straws to match the diagonal length of each silicone mould cavity, then press them diagonally into the ice-cream to create a channel for sipping tea through later. Ensure they are level with the mould’s surface for easy removal later, then freeze for four hours, or overnight.
7. To make the biscuits, combine the butter and sugar in a stand mixer with the paddle attachment fitted. Mix on low speed until creamy, then gradually add in the golden syrup, followed by the milk. Sift the flour, cocoa powder and bicarb soda into a large bowl, then add to the stand mixer in thirds, followed by the salt, until the mixture forms a thick dough. Increase the speed of the mixture and mix on high for 1 minute, then remove the dough. Cut two rectangles of baking paper 30 cm x 40 cm. Place the cookie dough between the two sheets of baking paper.
8. Place 2 x 30 cm metal rulers on either side of the cookie dough between the sheets of baking paper, then roll out to 3 mm thick, using the rulers as a guide, ensuring you have a perfect rectangle of dough that is the exact size of the baking paper.
9. Remove the top layer of baking paper, then use a roller docker or fork to prick the dough. Remove the rulers from the sides of the dough, then mark out a grid of 5 x 3cm rectangles on the dough, taking care not to cut the baking paper underneath the dough.
10. Avoid moving the rectangles of dough so that you keep the edges neat — they may fuse together as they freeze but it's super easy to snap the biscuits once they are frozen. Put the baking paper back on top then freeze for 10 minutes.
11. Preheat the oven to 170˚C. Remove the dough from the freezer; peel away the top sheet of baking paper and then place it back on. Flip the dough over onto the loose baking paper sheet, then remove the baking paper underside, snap and separate the biscuits. Transfer the biscuits to a baking tray lined with a silicone mat, then bake for 10 minutes.
12. Remove from the oven and cool to room temperature.
13. To make the magic chocolate dip, melt the cocoa butter in a small saucepan over a low heat – do not allow the temperature to exceed 60˚C. Place the chocolate into a heatproof bowl, then pour over the melted cocoa butter, stirring to combine. If there are still a few lumps in the dip, place it in the microwave and heat in 20 second bursts until fully melted.
14. To assemble, lay out the biscuits on a tray and remove the ice-cream from the freezer. Carefully pull the straws out of the ice-cream and discard. Push the ice cream pucks out of the silicone mould (the ice cream needs to be frozen solid to do this) and place neatly on half of the biscuits. Place the second half of the biscuits on top, lightly pressing them down, and leave at room temperature for a few minutes so that the ice cream melts a little and they stick together. Freeze for 2 hours.
15. Heat the magic chocolate dip to 35˚C. Insert a long skewer into the diagonal hole of the ice cream sandwich, dip the whole thing into the chocolate and quickly remove it, ensuring the chocolate does not block the straw hole. Place the dipped biscuit onto a tray lined with baking paper and repeat with the remaining sandwiches. Freeze until ready to eat.
16. When ready to serve, remove an ice-cream sandwich from the freezer and allow to stand for 2 minutes to soften. Bite off the two corners with straw holes, dip one end into the tea and sip the tea through the biscuit before taking a bite.