Tart and sweet with a nutty crunchy base — we could eat these all day long. They are a perfect afternoon snack with a cup of tea and make a great dessert topped à... la mode with a little scoop of good vanilla ice cream or Greek yogurt. These little delights pack flavor, phytonutrients, and are a good source of fiber.
Preheat the oven to 350 degrees. Butter and line 9 x 9-inch pan with two pieces of overlapping parchment.
Pour the hazelnuts onto a sheet tray and bake until fragrant and deep brown, about 10 to 12 minutes. Keep an eye on them so they do not burn. Remove from the oven and, once cool enough to handle, peel skins off with fingertips or a kitchen cloth.
In a food processor pulse the hazelnuts, pastry flour, oats, brown sugar, cinnamon, salt, baking powder, and baking soda. Pulse until the nuts are coarsely chopped, and the other ingredients are well combined. Add the butter and pulse until an even loose crumb forms.
Reserve 1½ cups of the dough, and tip the rest into the prepared baking pan. Press dough evenly and tightly into the pan, making sure to reach the edges. Bake for 12 minutes, then let cool.
Meanwhile, in a medium bowl prepare the filling. Whisk together the maple syrup, flour, and lemon zest. Stir in the raspberries and press them against the side of the bowl to break them up.
Spread the raspberry filling onto the slightly cooled crust. Sprinkle with the reserved topping and bake for 30-35 minutes or until the filling is bubbling the sides of the crust is golden and crisp. Let cool completely before cutting into bars.
You can make these bars with blackberries or blueberries too. They won’t have the tart bite of raspberries, but they will be sweetly delicious in their own way.