Preheat oven to 350 degrees Fahrenheit and line an 8×8 inch pan with parchment paper.
In a bowl, mix flour, sugar, and salt. Add butter and mix until crumbly.
Set aside 3/4 of the crumble mixture for topping.
Press the remaining 1/4 into the pan to form the base. Bake for 10 to 12 minutes.
In another bowl, mix sugar and flour. Add egg, sour cream, and vanilla extract. Whisk until smooth.
Fold in drained pineapple chunks.
Pour filling over the baked base and spread evenly.
Sprinkle remaining crumble mixture over the top. Do not press.
Bake for 30 to 35 minutes until set and lightly golden.
Cool completely, slice, and serve.