Homemade Tagalong Cookies

Make the shortbread dough: In a large bowl, cream together the softened butter and granulated sugar with an electric mixer until pale and fluffy. Mix in vanilla extract. Gradually add flour and salt and mix just until combined into a soft dough.
Roll and cut the cookies: Place the dough between two sheets of parchment paper. Roll to 1/4 inch thickness. Use a 2-inch round cookie cutter to cut out circles. Transfer to a parchment-lined baking sheet. If dough softens too much, chill for 5–10 minutes before cutting more shapes as needed.
Bake and cool: Bake at 350°F (180°C) for 10–12 minutes, until edges just begin to turn golden. Remove and let cool completely on a wire rack.
Make the peanut butter filling: Stir together peanut butter and powdered sugar in a medium bowl until smooth and pliable. Roll a teaspoon of filling into a ball, flatten gently, and press one onto each cooled cookie.
Chill the assembled cookies: Place tray of topped cookies in the freezer for 8–10 minutes, until peanut butter is firm.
Dip in melted chocolate: Melt chocolate wafers in a microwave-safe bowl in 20–30 second bursts, stirring after each until smooth. Using a fork or dipping tool, dip each chilled cookie into the chocolate, letting excess drip off. Return to parchment-lined tray.
Let them set: Allow chocolate to harden at room temperature or refrigerate for 15 minutes, until fully set.