Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal.

In a medium saucepan, combine the chopped dates, water, orange juice, and orange zest. Bring to a boil over medium-high heat.

Reduce the heat to low and simmer for about 10-15 minutes, stirring frequently, until the dates break down and the mixture becomes a thick, spreadable paste. Remove from heat and let cool slightly.

In a large mixing bowl, whisk together the rolled oats, flour, brown sugar, baking soda, and ground cardamom.

Add the cubed cold butter to the dry ingredients. Use a pastry cutter or your fingers to rub the butter into the mixture until it resembles coarse crumbs.

Press approximately two-thirds of the oat mixture firmly into the bottom of the prepared baking pan to form the base crust.

Spread the date filling evenly over the crust using a spatula.

Sprinkle the remaining oat crumble mixture evenly over the top of the date layer. Press down very lightly.

Bake in the preheated oven for 35 to 40 minutes, or until the top is golden brown.

Allow the squares to cool completely in the pan on a wire rack before lifting them out and slicing. This ensures they hold their shape.