Preheat the oven to 350F.

Line a 9 x 9 inch pan with parchment paper.

Mix together flour, baking powder, and salt in a bowl.

In a separate bowl, cream the butter and sugar with a hand mixer or a standing mixer on medium for 1-2 minutes, until it is light and fluffy. Scrape down the sides of the bowl with a spatula and add the egg. Mix until incorporated. Add the lemon juice and continue mixing, pausing to scrape down the sides a few times. It might look curdled, this is normal.

Add dry ingredients to wet ingredients and mix until combined.

Remove the bowl from the mixer and gently fold in diced strawberries and chocolate chips with a large spoon or rubber spatula. It might look a little pink, but this fades when you bake it.

Pour the mixture into the prepared pan and spread it around, pushing towards the edges and making the top even.

Bake 25-30 minutes. Try not to overbake them. The edges will be brown and a toothpick will come out clean when you pierce the middle.

Let them cool on a cooling rack and make sure they are fully cooled before cutting them into squares.