Sourdough Discard Thumbprint Cookies

Ingredients

Cookie Dough

• 113g (½ cup) unsalted butter, softened — Room temperature - should dent when pressed
• 100g (½ cup) granulated sugar
• 1 large (1 large) egg yolk — Save the white for another use
• 5ml (1 tsp) vanilla extract
• 113g (½ cup) sourdough discard, unfed — Straight from the fridge works perfectly
• 156g (1¼ cups) all-purpose flour
• 2g (½ tsp) baking powder
• 1g (¼ tsp) salt

Filling

• 120-180ml (½ - ¾ cup) jam or jelly of your choice — Raspberry, apricot, or strawberry work great

Equipment

• Stand Mixer or Hand Mixer
• Mixing Bowls
• Baking Sheets
• Parchment Paper
• Wire Cooling Rack
• Digital Scale (optional)

Method

Make the Dough

Cream butter and sugar, then fold in the sourdough discard. The discard adds moisture and a subtle tang that balances the sweetness.

1. Cream Butter and Sugar. Beat softened butter and sugar together until light and fluffy, about 2-3 minutes on medium speed.
2. Add Wet Ingredients. Beat in the egg yolk, vanilla extract, and sourdough discard until well combined. Mixture may look slightly curdled—that's fine.
3. Combine Dry Ingredients. In a separate bowl, whisk together the flour, baking powder, and salt.
4. Fold Together. Add the dry ingredients to the wet ingredients. Fold with a spatula until just combined. Don't overmix or the cookies will be tough.

Chill the Dough

Chilling firms the butter back up and makes the dough much easier to roll into balls.

1. Cover the Dough. Place plastic wrap or a lid directly on the dough surface.
2. Refrigerate. Chill for 30 minutes.
3. Preheat Oven. While dough chills, preheat oven to 350°F (175°C) and line two baking sheets with parchment paper.

Wait: Chill Time

Shape and Fill

Roll, indent, and fill. This is the fun part.

1. Roll into Balls. Scoop dough and roll into balls about 2.5cm (1 inch) in diameter.
2. Space on Sheets. Place balls 5cm (2 inches) apart on lined baking sheets.
3. Make Indents. Use your thumb or the back of a small spoon to press a well into the center of each cookie. If the edges crack, gently press them back together.
4. Fill with Jam. Spoon about ½ teaspoon of jam or jelly into each indent. Don't overfill—the jam bubbles and expands during baking.

Shape the Cookies

Classic thumbprint shape with jam-filled center

1. Roll into Balls. Roll dough into 2.5cm (1 inch) balls for standard size, or 4cm (1.5 inch) for larger cookies.
2. Create Indent. Press thumb or spoon back into center to create a well for the filling.
3. Fill Center. Add ½ teaspoon jam per cookie. For larger cookies, use up to 1 teaspoon.

Bake the Cookies

Bake until the edges just start turning golden. These carry over quite a bit after coming out of the oven, so pull them early.

Oven: 175°C / 350°F.

Bake time: PT15M

Equipment: Baking sheets with parchment paper

1. Position rack in center of oven. Bake one sheet at a time for most even results.

Storage

• Room temperature: 3-4 days in an airtight container. Layer with parchment between layers.
• Refrigerated: Not recommended—cookies may become soggy.
• Frozen: Unbaked dough balls freeze for up to 3 months. Baked cookies freeze for up to 2 months but texture is best fresh.
• Refresh: Not needed—best enjoyed at room temperature.

Frequently Asked Questions

Can I use fed starter instead of discard?

Yes, but the flavor will be milder. Discard has more tang, which is what makes these interesting. Both work.

My dough is too sticky to roll. What should I do?

Chill it longer, up to an hour. If still sticky, add a tablespoon of flour at a time until workable. Wet hands help too.

Can I use different fillings?

Absolutely. Raspberry, apricot, and strawberry jams are classics. Lemon curd, Nutella, or dulce de leche all work. Even a square of dark chocolate pressed into the center before baking.

The jam bubbled over during baking. What happened?

Too much filling. Use just ½ teaspoon per cookie. Also make sure the indent is deep enough.

Can I make these ahead?

Yes. Roll and indent the dough balls, place on a sheet, and freeze. Once solid, transfer to a bag. Bake from frozen, adding 2-3 minutes to bake time. Fill with jam before baking.

What do I do with the leftover egg white?

Brush it on bread before baking for extra shine, add it to scrambled eggs, or freeze it for later use.

Nutrition

Per serving (1 cookie): 95 calories, 12g carbohydrates, 1g protein, 5g fat, 0g fiber, 35mg sodium.