Preparation

Cream the Butter

• Place the softened butter into the bowl of a stand mixer (or a large bowl with a hand mixer). Beat until smooth and creamy.

Add the Sugars

• Scrape down the bowl, add both sugars, and mix. Gradually increase the speed to medium-high and beat for 30–60 seconds, until light and well-combined.

Add Egg Yolk & Vanilla

• Mix in the egg yolk and vanilla extract until fully incorporated.

Whisk Dry Ingredients

• In a separate bowl, whisk together the flour, cornstarch, and salt.

Combine Wet & Dry

• With the mixer on low, slowly add the dry ingredients to the butter mixture.
• The dough will look dry and crumbly—this is normal. Pause to scrape the bowl as needed.
• If the dough gets too stiff for the mixer, use your hands to bring it together.

Shape the Dough Balls

• Scoop out 1 tablespoon of dough and roll it into a smooth, round ball with no visible cracks.
• (Smooth dough = fewer cracks in the baked cookies.)

Roll in Sugar (Optional)

• If desired, roll each dough ball in granulated sugar for extra sparkle and sweetness.

Press Indents

• Place dough balls on a wax-paper–lined tray.
• Use your thumb—or the rounded back of a teaspoon—to gently press a small indent into each center.

Freeze the Dough

• Transfer the shaped cookies to the freezer and chill for 30 minutes.
• (This helps them keep their shape while baking.)

Prepare Oven & Jam

• Preheat oven to 375°F (190°C).
• Place the jam in a microwave-safe dish and warm for 5–10 seconds—just until it loosens and becomes easy to stir.

Fill the Thumbprints

• Spoon the warmed jam into each indent, filling right to the top.

Bake

• Place the cookies 2 inches apart on a parchment-lined baking sheet.
• Bake for 11 minutes, or until the edges turn lightly golden.

Cool & Serve

• Allow the cookies to cool completely on the baking sheet before lifting or serving.