To make a mandarin cake from scratch, start by preheating your oven to 180°C. Grind 250g of shortbread cookies into crumbs and mix them with 150g of melted butter and a pinch of salt. Press this mixture into a baking tin to form the crust and bake for 15 minutes. For the filling, whisk together 4 large egg yolks, 125g of mandarin juice, 1 tablespoon of mandarin zest, and 1 can of sweetened condensed milk. Pour this filling into the baked crust and return it to the oven for 17-18 minutes. Let it cool and refrigerate for at least 3 hours before serving.

This mandarin cake recipe is not gluten-free as it uses shortbread cookies, which typically contain wheat flour. However, you can easily make it gluten-free by substituting the shortbread cookies with gluten-free cookie crumbs or a gluten-free crust alternative. Just ensure that all other ingredients are also gluten-free.

If you need a substitute for sweetened condensed milk in the mandarin cake, you can use a mixture of evaporated milk and sugar. Combine 1 cup of evaporated milk with 1 1/4 cups of sugar and heat gently until the sugar dissolves. Alternatively, you can use coconut milk mixed with sugar for a dairy-free option.

To store leftover mandarin cake, cover it tightly with plastic wrap or place it in an airtight container. It can be kept in the refrigerator for up to 3-4 days. For longer storage, you can freeze the cake by wrapping it well in plastic wrap and then in aluminum foil. Thaw it in the refrigerator before serving.

Mandarin cake pairs wonderfully with a dollop of whipped cream or a scoop of vanilla ice cream for added creaminess. You can also serve it with a light citrus salad or alongside a cup of herbal tea for a refreshing contrast. For a more indulgent experience, consider pairing it with a glass of sparkling wine or champagne.