Preheat oven to 350°F (175°C). Spray an 8x8-inch baking dish with nonstick spray or line with parchment paper.

In a large bowl, blend the flour, confectioners' sugar, and cold butter for the crust. You can use a food processor or pastry cutter, but using your hands works well. Mix until the butter is no bigger than pea-sized pieces and the ingredients are well incorporated.

Press the crust mixture evenly into the prepared baking dish.

Bake the crust for 12-15 minutes, or until the edges just begin to turn golden. Remove from the oven.

Spread the raspberry preserves evenly over the baked crust. Then, place the fresh raspberries evenly over the preserves.

For the topping: In a medium bowl, combine the cold butter, flour, confectioners' sugar, and quick oats. Using your hands, sift the flour over the butter and start breaking down each piece into pea-sized pieces to create a crumbly mixture.

Crumble the oatmeal topping mixture evenly over the raspberry filling.

Bake for 45-50 more minutes, or until the crumble topping is a light golden brown. Let the bars cool at room temperature for at least 30 minutes. Then, place them in the refrigerator to chill for at least 2 hours before adding icing.

For the icing: In a medium bowl, combine the confectioners' sugar, milk, and almond extract. Add more milk, one teaspoon at a time, until you reach your desired drizzling consistency.

Drizzle the almond icing over the chilled bars. Serve immediately, or keep chilled in the refrigerator if preferred.