Steps
1. Preheat your oven to 350°F (175°C).
2. In a small bowl, whisk together flour, baking powder, salt, and sugar.
3. In another bowl, mix the milk, melted butter, and vanilla extract.
4. Combine the wet and dry ingredients until just mixed.
5. Grease a small ramekin or oven-safe dish and pour half of the batter into it.
6. Add the fruit jam on top of the batter, then cover with the remaining batter.
7. Bake for 20-25 minutes or until a toothpick comes out clean.
8. Allow to cool slightly before enjoying your jam-filled vanilla cake.