Dulce de Leche Filled Cornstarch Cookies

Introduction

The high cornstarch content gives these cookies a soft, delicate crumb, while the lemon rind keeps the sweetness from tasting flat. You bake them for 15 minutes, keep them pale, and sandwich them with dulce de leche, which makes them a good choice for a cookie tray, gifting, or make-ahead dessert.

Recipe Details

• Prep Time: 25 minutes
• Cook Time: 15 minutes
• Total Time: 40 minutes
• Servings: 12 sandwich cookies

Ingredients

• ½ cup (120 ml) butter
• 1 cup (240 ml) white granulated sugar
• 1 egg
• 2 egg yolks
• 1 tsp vanilla
• 2 tsp lemon rind, grated
• 1½ cup (360 ml) cornstarch
• ½ cup (120 ml) flour
• 1 tsp baking powder
• ¼ tsp salt
• Dulce de leche

Instructions

1. Cream butter; add sugar and beat until fluffy.
2. Add egg and egg yolks one at a time, beating well. Beat in vanilla and lemon rind.
3. Sift together cornstarch, flour, baking powder, and salt. Add to batter and mix well.
4. Drop batter by small spoonfuls onto well-buttered baking sheet.
5. Bake at 350°F for 15 minutes. Remove immediately and cool.
6. Sandwich the cookies together with dulce de leche.

Variations

• Swap the lemon rind for the same amount of orange zest if you want a sweeter citrus note with less sharpness.
• Replace the ½ cup (120 ml) flour with a cup-for-cup gluten-free flour blend to make the cookies gluten-free; the finished cookies will be slightly more fragile.
• Roll the edges of the dulce de leche filling in finely shredded coconut after sandwiching the cookies for extra texture and a more classic alfajor-style finish.
• Dip half of each assembled cookie in melted dark chocolate and let it set; this adds a firm shell and cuts some of the sweetness.

Tips for Success

• Use softened butter for the first step so it creams properly with the sugar instead of staying dense and streaky.
• Sift the cornstarch, flour, baking powder, and salt well; cornstarch clumps easily and can leave dry pockets in the batter.
• Keep the spoonfuls small and even so the cookies bake at the same rate and match up cleanly for sandwiching.
• Pull the cookies at 15 minutes while they are still pale; if they brown much, they lose the tender texture these cookies should have.
• Cool the cookies completely before adding dulce de leche so the filling stays in place instead of melting and sliding.

Storage and Reheating

Store the assembled cookies in an airtight container with parchment between layers in the fridge for up to 5 days. The filling softens the cookies slightly over time, which is normal.

For longer storage, freeze the baked unfilled cookies in a freezer-safe airtight container for up to 2 months. Thaw at room temperature, then sandwich with dulce de leche.

These do not need reheating. If you store them in the fridge, let them sit at room temperature for 15 to 20 minutes before serving so the cookies soften slightly and the dulce de leche is easier to bite through.

FAQ

Why did my cookies come out dry or too crumbly?

You likely baked them too long or added too much cornstarch or flour by packing the measuring cups. These cookies should stay pale and tender, not dry and browned.

How much dulce de leche should you use for each sandwich?

Use about 1 to 2 teaspoons per cookie sandwich, depending on the size of your baked cookies. Add enough to reach near the edges without squeezing out heavily when pressed.

Can you make these gluten-free?

Yes. Replace the ½ cup (120 ml) flour with a cup-for-cup gluten-free flour blend; the cookies will hold together, but the texture will be a bit more delicate.

Can you make the dough ahead of time?

Yes. Cover the mixed dough and refrigerate it for up to 24 hours, then let it sit just long enough to become scoopable before baking.