Espresso Martini Ice Cream Sandwiches

For the ice cream

• 1 cup sweetened condensed milk (397 g)
• 1 ¼ cups double cream (300 mL)
• ½ cup coffee liqueur (100 mL)
• ½ cup whole milk (150 mL)
• ¼ cup espresso (50 mL)
• 1 teaspoon vanilla extract
• ¼ teaspoon sea salt

For the cookies

• 2 cups plain flour (250 g)
• ¼ cup cocoa powder (40 g)
• ¼ cup espresso powder (25 g)
• 5 g baking soda (5 g)
• 3 g sea salt (3 g)
• 1 cup unsalted butter (230 g), room temperature
• 100 g golden caster sugar (100 g)
• 1 cup light brown sugar (220 g)
• 2 large eggs
• 1 teaspoon vanilla extract
• 1 cup dark chocolate chips (150 g)
• 1 cup white chocolate chips (150 g)