1. Line a 20x20cm square baking pan with parchment paper. In a large bowl, combine the oats, flour, brown sugar, cinnamon, baking powder, and salt. Stir to combine.
2. Add the melted butter, vanilla, and honey, and mix well. Reserve 1 cup of this mixture for the topping and mix it with the coarsely chopped almonds. Place this mixture in the refrigerator.
3. Press the remaining mixture firmly into the bottom of the baking pan to create a compact and even base.
For the Homemade Apricot Jam (Filling):
1. Place the apricots, sugar, honey, and 3-4 tablespoons of the water in a small saucepan. Stir and place over heat. Bring to a boil and simmer over medium-high heat for 5 minutes. Add the vanilla extract, bitter almond essence, and salt. Stir. Dissolve the cornstarch in the remaining water, about 3 tablespoons, and add it to the apricots. Stir for a few seconds and remove from heat. Let cool for 10 minutes.
2. Preheat oven to 180°C (fan-assisted). Spread the filling evenly over the base. Sprinkle the reserved base mixture (crumble) from the refrigerator over the top, a little at a time. Bake for 45-50 minutes, or until the surface is golden brown and has a beautiful golden color.
3. Let the dessert cool completely in the pan. Ideally, let it set for 4-5 hours or overnight before cutting into bars. Store in an airtight container for up to 3 days at room temperature. If the weather is very hot, store in the refrigerator for up to 5 days.
