Preheat oven to 160°C. Grease a medium sized cake pan with butter and dust with flour.
In a bowl, sift together the flour, baking powder and salt, set aside.
In a small saucepan, heat milk and butter just until butter is melted.
In a big bowl, beat the condensed milk and sugar for 4-5 minutes until mixture is light and creamy. Add the vanilla and mix.
Carefully pour milk mixture into the creamed condensed milk, and mix for a minute or so.
Gradually add flour mixture in two batches and fold the mix gently together with a metal spoon using big scooping movements.
Then add lemon juice, lemon zest, chopped red chilli and nuts, fold the rest in very gently.
Pour the batter into a greased baking pan. Bake at 160°C for 44-50 minutes or until a toothpick inserted in the center comes out clean.
