20 to 24 servings
16 tablespoons (2 sticks) unsalted butter, margarine or coconut oil
3 cups ground almonds (may use almond meal or almond flour; see headnote)
1 1/2 cups ground walnuts
1 1/2 cups ground hazelnuts (skin-in or skinned)
1 cup potato starch or tapioca starch
1/2 cup granulated sugar, plus 1 1/2 teaspoons for sprinkling
1 cup confectioners' sugar, plus more for dusting
1 cup raspberry jam
1 cup apricot or other favorite jam
1 large egg white, beaten, for brushing
Use cooking oil spray to grease a 12-by-17-inch rimmed baking sheet (including its sides) with some oil and press in a piece of parchment paper large enough to cover the bottom and up the sides.
Grease the top of the parchment as well.
Place the butter, margarine or coconut oil in the bowl of a stand mixer or handheld electric mixer; beat for several minutes on high speed until soft and fluffy, stopping to scrape down the bowl once or twice.
Add the ground almonds, walnuts and hazelnuts, potato starch or tapioca starch and the 1/2 cup of granulated sugar; beat on low speed to form a dough.
Transfer a little more than half the dough to the lined baking sheet.
Use your hands to press the dough into the bottom to cover and up the sides. I find it easiest to press the dough into the sides and corners first with my fingers and then I use the palm of my hand to press dough to cover the pan bottom. If needed, take a little extra dough from what you separated out to cover the bottom.
Place into the freezer.
To the smaller piece of dough in the bowl, add the 1 cup confectioners' sugar and mix in; the easiest way is to use your hands or the mixer.
Shape into a ball and flatten. Do not worry if the dough is crumbly. Cover in plastic and place in the freezer for 45 minutes.
Preheat the oven to 375 degrees.
Remove the pan from the freezer. Bake (middle rack) for 10 to 15 minutes, or until the crust just starts to color.
Let cool until the top crust dough in the freezer is ready to be rolled out.
Take a piece of parchment paper and sprinkle with some confectioners' sugar.
Place the chilled dough on top, sprinkle with more of the sugar and cover with another piece of parchment.
Roll on top of the parchment to roll the dough to a thickness of 1/3 inch in the shape of a rectangle as best as you can. Every few turns with the rolling pin, lift up the top parchment and sprinkle a little more confectioners' sugar on top of the dough so that it does not stick.
Use a knife or pastry wheel to cut the dough into 12 to 14 one-inch strips. Slide the parchment and cut strips onto a separate baking sheet; freeze them for 10 minutes so that they firm up.
Position the baking sheet on the countertop so that a long side is parallel with the edge of the counter.
Use a small spoon to scoop up some raspberry jam and starting at the left, spoon 4 clumps of jam from the top to the bottom at 2-inch intervals, then use the back of the spoon to spread the jam evenly down that row to make about a 1 1/2-inch vertical row of jam.
Use another spoon to scoop up 4 clumps of apricot jam and drop at intervals to the right of the first row of jam and use the back of the spoon to spread the jam evenly down that row.
Repeat with the raspberry jam and then alternate rows so that you have stripes of jam alternating in colors. Use up all the jam.
Remove dough strips from the freezer and use a long metal spatula or big knife to lift up and place the strips diagonally across the top of the jam-filled crust first on one angle and then the other to create a lattice look.
Place all the strips in one direction an inch or two apart and then place the others in the other direction. Do not try to bend the strips back to make a perfect over and under lattice.
Trim the dough at the ends and press into the sides of the crust in the pan.
Brush the strips with the beaten egg white and sprinkle with the remaining granulated sugar.
Bake for 30 to 35 minutes, or until jam is bubbling and the crust is golden brown.
Let it sit for a few minutes before serving.
From cookbook author and baking instructor Paula Shoyer. The Washington Post