Combine milk, custard powder and sugar and cook till the sauce thicken.

Switch off, add the butter and vanilla essence and whisk till the butter melts. Set aside to cool.

Preheat oven to 180 degrees. Grease a small pan and keep aside.

Cream butter and sugar till fluffy. Add the egg and beat till well combined.

Whisk together the dry ingredients and add into the beaten mixture.

Fold in till well combined. The batter will be very thick.

Spread half the batter into the pan. Top with the custard and then with the remaining of the batter. This process can be tricky but not necessary it coats well.

Bake for around 35 to 40 minutes till the top is golden.

Serve warm with some whipping cream on the side or with a dash of icing sugar on the top, or with some ice cream and chocolate sauce!