Make the shortbread dough: Preheat your oven to 350°F and line a large baking sheet with parchment paper. In a bowl, cream together the softened butter and sugar until light and fluffy. Mix in the flour and salt until a soft, crumbly dough comes together.

Roll and cut: Lightly flour your work surface and roll the dough out to about ¼ inch thick. Use a Christmas tree cookie cutter to cut out your trees, then gently transfer them to the prepared baking sheet.

Chill: Pop the tray in the fridge for about 1 hour and 30 minutes so the dough firms up — this helps the cookies hold their shape when baking.

Bake: Bake the shortbread for 18–20 minutes, or until the edges are just turning golden. Let them cool completely on the pan before moving them to a wire rack.

Make the caramel: In a medium saucepan over medium heat, melt the butter, then stir in the brown sugar, sweetened condensed milk, corn syrup, and salt. Keep stirring for about 8–10 minutes, until the mixture thickens and turns golden.

Top the cookies: Line a new baking sheet with parchment paper. Place the cooled shortbread trees on it, then spoon a layer of warm caramel over each cookie, spreading it gently to the edges. Let them set for about 30 minutes at room temperature.

Add the chocolate: Melt the chocolate chips and oil together in the microwave in 30-second bursts, stirring between each, until smooth and glossy. Spoon or spread the chocolate over the caramel layer of each tree. Chill for 2–3 hours, or until the chocolate has firmed up completely.

Decorate: Once set, drizzle with a little extra melted chocolate and finish with Christmas sprinkles for a festive touch. Let them set, then serve or wrap them up for the sweetest homemade holiday gift.