Ingredients

   
208g AP flour
2g baking powder
2.5g baking soda
1.5g salt
113g unsalted butter, softened
200g granulated sugar
1 large egg
9g vanilla extract
12g espresso powder
20g sweetened condensed milk
100g granulated sugar, for rolling

Steps

  1. Preheat oven to 350°F. Line baking sheets with parchment.

  2. Whisk together flour, baking powder, baking soda, and salt. Set aside.

  3. Cream the softened butter and 200g sugar until light and fluffy, 2–3 minutes. Beat in the egg and vanilla until smooth.

  4. Gradually add the dry ingredients, mixing just until combined. Do not overmix.

  5. Divide the dough: ⅔ into one bowl, ⅓ into another. Mix the espresso powder into the larger (⅔) portion until evenly colored. Mix the condensed milk into the smaller (⅓) portion.

  6. For each cookie, take about 2 tablespoons of coffee dough and 1 tablespoon of condensed-milk dough. Gently press together and roll into a ball (~50g). Don’t overwork — you want visible marbling.

  7. Roll each ball in the 100g rolling sugar to coat. Space well apart on the sheets.

  8. Bake 12–14 minutes until the edges are lightly golden. Cool on the sheet a few minutes, then transfer to a rack.

Analysis

Total batter weight: 618g (dough; the 100g sugar coating is excluded — see below)

Component Amount %
Structure solids (flour) 208g 33.7%
Fat (butter, egg) 98g 15.9%
Sugar (granulated + condensed milk) 215g 34.8%
Liquid (vanilla, butter water, egg water, condensed milk water) 71g 11.5%
Egg/protein 26g 4.2%

A creamed drop cookie built to spread flat: high sugar (35%) plus both baking soda and powder drive the spread, while moderate fat (16%) and 34% structure give a thin, crisp-edged round with a chewy middle. The 100g rolling sugar is a finishing coat, not dough — excluded here so the denominator stays the actual batter. To make them thicker, the notes cut the soda and add cornstarch.

Notes

  • A creamed drop cookie, so it bakes into a thin, crisp-edged round with a slightly chewy center — flat is the intended result. The sugar coating gives a crackly crust.
  • The espresso flavor is bold at 12g. For a gentler coffee note start at 8g. Vietnamese instant coffee (Vinacafé, G7) gives a maltier, more authentic flavor than espresso powder.
  • Marble effect: the less you combine the two doughs, the bolder the swirl. A couple of presses is enough.
  • Cookies spreading too thin? Chill the rolled, sugar-coated balls 30 minutes before baking and make sure the butter was softened but not melted. Overmixing also makes them tough and flat.
  • Want them thicker and cakier: drop the baking soda, keep only the baking powder, add 10g cornstarch, scoop taller, and bake at 375°F so the edges set before they spread.
  • Add a tablespoon of cocoa to the coffee dough for a mocha version. A pinch of cinnamon is nice in autumn.
  • Store airtight at room temperature up to 5 days; a slice of bread in the container keeps them soft. Dough freezes up to 2 months — bake shaped balls from frozen, adding a few minutes.