These cookies are oh so cute and yummy! I'd write something clever about them, but I really am just sitting here wondering when I can sneak another one. ;) So, let's get to it!
16 TBSP (2 sticks) unsalted butter at room temperature
2/3 C + 3 TBSP confectioner's sugar
1 large egg yolk
1 tsp vanilla extract
2 1/2 C all-purpose flour
1/4 tsp salt
2/3 C raspberry jam
1. Preheat oven to 325*F; line 2 baking sheets with parchment. Beat butter and 2/3 C sugar until fluffy. Beat in egg yolk and vanilla, then flour and salt. Shape dough into 2 disks; wrap 1 in plastic and refrigerate.
2. On a floured surface, roll out remaining disk to about a 1/8 inch thickness. Cut out cookies with a 2 1/2 inch heart shaped cookie cutter. Use a smaller heart cutter to cut a window our of half of the cookies. With a spatula, carefully transfer to prepared cookie sheets. Repeat with remaining dough. Gather scraps and roll out again to make more cookies.
3. Bake cookies in batches until edges of cookies are just golden, 10-12 minutes. Let cool for 5 minutes, then transfer cookies to wire rack to let cool completely.
4. Spread 3/4 tsp jam over flat side of each cookie that doesn't have a window. Top with remaining cookies, flat side down, so jam shows through the windows. Carefully sift 3 TBSP confectioner's sugar over the cookies.