
Pre-heat oven to 350F/180C. Grease and flour, spray or line an 8 inch/ 20cm round cake pan.
In a large bowl whisk the flour, sugar, baking powder and salt (and zest if using). Add the butter, egg and vanilla combine to form a crumbly mixture.
Place half the mixture on the bottom of the prepared pan and gently press down. Spread the jam on top and cover with the chopped strawberries. Cover with the remaining crumb mixture.
Bake for approximately 30-35 minutes or until golden on top. Let cool 20-25 minutes in the pan then move to a clean plate to cool completely. Dust with powdered sugar before serving. Enjoy!