For the cookies:
- 2 sticks (8 ounces) unsalted butter, cut into chunks and at room temperature
- 1/2 cup granulated sugar
- 1/4 cup powdered sugar, sifted
- 1/2 teaspoon salt
- 2 large egg yolks, at room temperature
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- Cooking spray or butter
For the streusel:
- 3/4 cup all-purpose flour
- 3 tablespoons granulated sugar
- 1 tablespoon packed brown sugar
- 1/4 teaspoon ground cinnamon
- 1/4 teaspoon salt
- 5 1/2 tablespoons (2 3/4 ounces) unsalted butter, cold and cut into small cubes
- 1/2 teaspoon vanilla extract
- About 1/2 cup thick jam, such as blueberry or raspberry
Make the dough:
- Place the butter, granulated sugar, powdered sugar, and salt in the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed, scraping the bowl as needed, until smooth but not fluffy, about 3 minutes. (Alternatively, use a large bowl and an electric hand mixer.)
- Reduce the mixer speed to low and beat in the yolks one at a time, followed by the vanilla. Turn off the mixer, pour in the flour all at once, and pulse the mixer until the risk of flying flour has passed. With the machine on low, mix just until the flour disappears into the dough. Give the dough a couple of turns with a sturdy rubber spatula.
- Turn the dough out onto the counter, divide it in half, gather each piece into a ball, and shape into a disk.
- Working with one piece of dough at a time, roll the dough 1/4-inch thick between 2 sheets of parchment. Slide the parchment-sandwiched dough onto a baking sheet (you can stack the sheets of dough) and freeze for at least 1 hour or refrigerate for at least 2 hours. (Wrapped airtight, the dough can be frozen for up to 2 months or refrigerated for up to 2 days.) Meanwhile, make the streusel.
Make the streusel:
- Whisk the flour, granulated sugar, brown sugar, cinnamon, and salt together in a clean stand mixer fitted with the paddle attachment. (Alternatively, use a large bowl and your fingers.) Drop in the cubes of cold butter and toss all the ingredients together with your fingers until the butter is coated.
- If you’re continuing by hand, squeeze, mash, mush, or otherwise rub everything together until you have a bowl full of moist clumps and curds. Squeeze the streusel and it will hold together. Sprinkle over the vanilla and toss to blend.
- If you’re working with a mixer, mix on medium-low speed until the ingredients form moist, clumpy crumbs. Squeeze the streusel and it will hold together. Reaching this stage takes longer than you think it will — you might have to mix for 10 minutes or more (note: this was the one part of the directions where my experience different – 5 minutes in, the streusel was almost a paste, it was over mixed – I had to re-crumble. So, keep a close eye for the clumpy crumbs!). When the grainy crumbs have turned moist and form clumps and curds, sprinkle over the vanilla and mix until blended.
- Pack the streusel into a covered container and refrigerate for at least 1 hour (3 would be better) before using.
- Arrange a rack in the middle of the oven and heat to 350°F. Coat the wells of a 12-well muffin tin with butter or cooking spray. (If you’ve got 2 tins, use both of them and arrange 2 racks to divide the oven into thirds instead.) Have a 2-inch round biscuit or cookie cutter at hand.
Assemble the cookies:
- Working with one sheet of dough at a time (keep the other one refrigerated), peel away both sheets of parchment paper (it’s hard to cut the dough otherwise); put the dough back on one sheet. Cut out rounds of dough with a 2-inch round cutter. Drop a round into each muffin well. (Save the scraps, combine, gather them together, re-roll, chill and cut.) Don’t worry if the dough doesn’t completely fill the molds, it will once it’s baked.
- Spoon about 1/2 teaspoon jam in the center of each cookie. Spoon or sprinkle streusel around the edges of each cookie – you want to cover the surface, but to leave the jam bare.
- Bake for 11 minutes. Rotate the baking sheet from front to back (and between racks if baking 2 tins). Bake until the streusel and the edges of the cookies are golden brown, 9 to 11 minutes more. The jam may bubble and that’s fine. Leave the cookies in the tins for about 15 minutes before transferring them to a rack to cool to room temperature.
Repeat with the remaining dough, letting the tins cool between batches.