Preheat the oven to 160C and line a 9" x 9" baking pan with parchment paper. Set this aside.

You can use a stand mixer or electric hand mixer for this first step, or a whisk, it's up to you.Cream the butter and sugar together until light and fluffy. Then add the egg and continue to beat until well combined.

Now add the sourdough starter and continue to beat until it's all mixed together. Set this aside for just a minute while you work on the dry ingredients.

In a separate bowl, combine the all purpose flour, baking powder and salt. Whisk until well combined. Add the strawberries and lemon zest and fold them through the flour until they are well coated.

Now, add the flour and strawberry mixture to the butter, sugar and egg mixture, folding together until there's no more dry flour (just don't over mix at this point).

Add the strawberry bar batter to the pan you prepared earlier and bake for around 30 to 35 minutes. You want the middle to still be slightly moist when you take it out of the oven.

While the bars are baking, grab a bowl and add the diced strawberries sprinkled with just a little bit of the powdered sugar. Mash them up with a fork until they look like the photo on the right.Then, add the rest of the powdered sugar and lemon juice to the strawberries and whisk together to form the strawberry glaze.

Once the sourdough strawberry bars are cool, pour the glaze over and allow to set before slicing into 9 squares. I like to set the glaze in the fridge before slicing, but it's up to you whether you do this.