To make the strawberry ripple, in a small saucepan, combine the strawberries, ¼ cup (55g) of sugar and the lemon juice. Bring the mixture to a simmer over medium heat, mashing the berries with a potato masher or fork to break them up. Simmer the mixture, stirring frequently, for 18 mins or until it thickens. Transfer the mixture to a bowl, cover and refrigerate until cold.
Spoon one-third of the ice-cream into a small, shallow baking dish, forming a layer to cover the bottom of the dish (the layer doesn’t have to be perfect). Dollop half of the strawberry mixture over. Top with another layer of ice-cream. Repeat the layering. Cover and freeze for 1 hour or until firm.
Meanwhile, make the biscuits. Preheat the oven to 175°C. Line 2 large baking trays with baking paper.
In a small bowl, sift the flour, bicarbonate soda, baking powder and ¼ tsp sea salt flakes. In a large bowl, beat the butter and ¾ cup (165g) of the sugar on medium speed for 3 mins or until pale and fluffy. Add the egg and beat for 1 min or until blended. Reduce the speed to low. Gradually add the flour until the dough comes together. Using a tablespoon, scoop the dough into 16 rounded mounds onto a baking tray and freeze for 5 mins or until the dough is firm enough to roll. Shape the dough into balls and roll in additional sugar to coat. Place the balls about 10cm apart on the prepared baking trays. Using the bottom of a glass, flatten the balls into 6cm rounds.
Bake the biscuits for 8-10 mins or until the edges are lightly golden. Let the biscuits cool on the trays for 5 mins before transferring to a wire rack to cool completely.
To assemble the ice-cream sandwiches, spoon the strawberry ripple ice-cream onto the flat side of half of the biscuits. Place another biscuit on top of the ice-cream and gently press down until the ice-cream has spread to the edges. Return the sandwiches to the freezer for about 30 mins or until firm, and then serve.