Crust:

1. Preheat your oven to 150°C.
2. Line a 20 cm square glass dish with baking parchment, leaving a bit of overhang to make lifting the bars easier later. Set aside.
3. In a medium bowl, combine 1/4 cup castor/caster sugar, 1 tsp. vanilla essence, 1 cup of cake flour, 1/4 tsp salt, and 125 g melted butter.
4. Stir until it’s all evenly mixed (don’t overwork it).
5. Press the crust into your prepared dish, spreading it out evenly. Bake for 15 minutes.

While the crust is baking, make the streusel:

1. In a small bowl, mix 1/2 cup raw oats, 1/3 cup light brown sugar, 1/4 tsp cinnamon, 1/4 cup of cake flour, and 50 g cold butter cubes.
2. Rub the butter into the dry ingredients with your fingers until it looks like chunky crumbs.
3. Remove the crust from the oven and increase the oven temperature to 180°C/350°F.
4. Spread 250 g raspberry jam over the warm crust, then scatter 12–16 fresh raspberries on top.
5. Scatter your oat-butter mixture evenly over the jam and raspberries.
6. Bake for 15 minutes, or until the topping is lightly golden.

Optional glaze:

1. Mix 1/4 cup icing sugar with 2–3 tsp. of milk and drizzle over the warm bars for a sweet finish.
2. Cool completely in the pan, then lift out using the parchment overhang.
3. Slice into squares or rectangles and enjoy!

Tip: Bars keep well in an airtight container for up to 4 days.