Preheat your oven to 200C / 400F / Gas mark 6 and lightly grease or line an 8 x 8 inch pan with baking parchment.
Melt your butter in the microwave for about 30 seconds, you want it just melted and not boiling.
Mix the melted butter with the milk, egg and vanilla extract in a large mixing bowl until everything is well combined.
Stir in the all the remaining ingredients (except the fruit) all at once till you have a lumpy batter. Like all quick-breads you don't want to over mix this batter
Gently mix in the fruit right before you add the batter to your pan.
Pour the batter into your prepared pan smooth the top and pop it in your oven.
Check on your cornbread after 35 minutes, you are looking for a firm golden top and a tooth pick to come out clean when entered then removed from the centre. If the pick is not 100% clean give it another few minutes then check again.
Once your cornbread is ready take it out of the oven and leave it in the pan for a few minutes to cool down a little bit.
Then carefully take the cornbread out of it's tin and allow it to fully cool down on a wire rack.
Kept in an airtight tin this cornbread should keep for up to 5 days.