BEURRE & SEL JAMMERS

Steps:

• For cookie dough:
• Using an electric mixer at medium speed, beat butter in a large bowl until smooth and creamy, about 3 minutes. Add both sugars and salt; beat until well blended, about 1 minute. Reduce speed to low; beat in egg yolks and vanilla. Add flour and mix just to combine. Dough will be soft and slightly sticky.
• Divide dough in half. Place each half between sheets of parchment or waxed paper. Flatten dough into disks. Working with 1 disk at a time, roll out dough, occasionally lifting paper on both sides for easy rolling, until 1/4" thick. Freeze dough in paper until firm, at least 2 hours. DO AHEAD: Dough can be made 2 days ahead. Cover and keep frozen.
• For streusel:
• Mix flour, sugar, and salt in a small mixing bowl. Using your fingertips, rub butter and vanilla into dry ingredients until no large lumps remain and butter is well incorporated. Streusel will be sandy and hold its shape when pressed between your fingers. Cover and chill. DO AHEAD: Streusel can be made 2 days ahead. Keep chilled.
• For assembly:
• Arrange a rack in middle of oven; preheat to 350°F.
• Using cookie cutter, cut out rounds of frozen dough from freezer. Place rounds in bottom of muffin cups and gently pat to flatten. Continue cutting frozen dough into rounds; gather scraps and repeat process of rolling out and cutting to make 34 rounds. Cover muffin tins with foil and chill in freezer until dough is firm, about 30 minutes or up to 2 days.
• Spoon about 1 teaspoon jam into the center of each round of dough. Using your fingers or a small spoon, sprinkle 1-1 1/2 tablespoons streusel around edges of each cookie, trying not to get any in the jam.
• Bake cookies, in batches if needed, until sides and streusel are golden, 20-22 minutes. Let cool in tins for 15 minutes. Run a small knife around edges of muffin cups; gently remove cookies and let cool completely on a wire rack. DO AHEAD: Cookies can be baked 2 days ahead. Store airtight at room temperature.