Strawberry Thumbprints

I found this recipe on the Family Circle website in 2006. I make it every year at Christmas and it's the one recipe that everyone asks for! The dough is very crumbly so you have to press it together firmly to have it keep it's shape.

• Ready In: 13 mins
• Serves: 1
• Yields: 3 dozen

Ingredients

• 3⁄4 cup unsalted butter, at room temperature
• 1  cup sugar, divided
• 1  egg yolk
• 2  teaspoons vanilla extract
• 1⁄2 teaspoon salt
• 1  cup ground walnuts
• 2  cups all-purpose flour
• 0.5 (12 ounce) jar  seedless strawberry jam

Directions

1. Beat butter, 1/2 c of the sugar, yolk, vanilla and salt until fluffy. Add walnuts and flour. Blend on low speed just until combined; dough will be crumbly but moist. Divide dough in half and form into two balls; wrap in plastic, refrigerate for 1 hour.
2. Heat oven to 375 degrees. Line 2 large baking sheets with parchment paper. Beak off 1 Tbsp of dough and roll into a ball (I use a cookie scoop). Roll ball in remaining 1/2 c sugar to coat. Place on prepared baking sheet. Press a deep indentation into the center of the dough, large enough for 1/2 tsp jam. Fill indentation with jam; repeat to form 36 cookies.
3. Bake cookies in preheated oven for 12-14 min, rotating pans halfway through, until lightly golden. Cool on pans on wire racks for 5 minutes. Transfer cookies to racks; cool completely.