Ingredients
Equipment
Method
Prep and make the dough
- Preheat oven to 350°F and line two baking sheets with parchment paper.
- In a large bowl, combine cake mix, eggs, vegetable oil, and vanilla extract, then stir until a soft dough forms.
Shape and press the wells
- Roll the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheets.
- Press your thumb or a rounded teaspoon into the center of each dough ball to create a deep well.
Bake
- Bake for 10–12 minutes at 350°F, until the edges are just set and the bottoms are lightly golden; do not overbake.
- If the centers puff up as they bake, gently re-press the wells with the back of a small spoon immediately after removing from the oven.
- Cool the cookies on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely for about 20 minutes.
Fill and finish
- Fill half of the cookies with 1/2 tsp red jam and fill the other half with 1/2 tsp blue jam.
- Optionally, add a dot of white frosting to some cookies for full red-white-blue variety.
- Garnish with sprinkles if desired, then serve at room temperature or refrigerate until ready to serve.
Notes
For the deepest thumbprint wells (so jam doesn’t spill), press firmly right after shaping. Store cookies in the fridge up to 3 days in an airtight container; bring to room temperature before serving for best texture. Freezing: yes, freeze unfilled baked cookies up to 2 months, then thaw and fill. Dietary swap: use a gluten-free vanilla cake mix if you need a gluten-free version (fillings stay the same).