Preheat oven to 350F. Line a baking sheet with parchment paper. Set aside.
Place melted butter and sugar in the bowl of a stand mixer fitted with a paddle attachment. Beat on medium speed until smooth. Add eggs, peanut butter, yogurt, and vanilla and mix until incorporated. Mix in flour, baking soda, and salt until a soft cookie dough forms.
Roll dough into 1-in balls and place on prepared baking sheet. Use your thumb to make an indention in the center of each ball. Fill each thumbprint with 1/2 to 1 tablespoon jam.
Bake cookies at 350F 10-11 minutes or until edges begin to turn golden. Cool cookies on baking sheet 10 minutes, then drizzle each cookie with warm melted white chocolate. Let set 5 minutes, then transfer cookies to a wire cooling rack to cool completely.
Notes
Store cookies in an airtight container at room temperature up to 2 days.