Step 1

Preheat oven to 180 Celsius (350 Fahrenheit), and line a 8"x8" square cake pan with parchment paper with an overhang to make it easier to release from the pan later.

Step 2

In a large mixing bowl, mix together all-purpose flour, oats, brown sugar, baking powder, and salt. Pour melted butter and mix well, then add the egg and mix again. This is our cookie dough mixture.

Step 3

Place 2 1/2 cup of the cookie dough mixture into the prepared pan, press to make the cookie base.

Step 4

Spread the pineapple jam over the cookie base, then crumble the remaining cookie dough mixture on top of the jam.

Step 5

Bake in the preheated oven for about 40-45 minutes, or until the top is golden brown.

Step 6

Remove from oven and let the cookie cool completely in the pan.

Step 7

Gently remove cookie from pan (that's why you want the paper overhang, to make this step easy), cut neatly into squares.

Step 8

You can cut however large or small you want, from 1"x1" tiny squares (64 tiny squares total), all the way to large 9 squares. Store leftovers in air-tight container.