Caramel Oatmeal Cookie Recipe

In a medium heavy-bottomed saucepan, combine 1 cup sugar and 1/4 cup water and stir gently to moisten. Cook over medium heat without stirring until mixture turns amber — swirl pan occasionally (about 8–10 minutes). Watch closely to avoid burning.

Once amber, remove from heat and carefully whisk in 6 tbsp butter (mixture will bubble). When butter is incorporated, slowly stream in 1/2 cup heavy cream while whisking until smooth.

Stir in 1/2 tsp salt and 1 tsp vanilla. Let cool 10–15 minutes, then transfer to a jar and cool to room temperature. Reserve 1/2 cup for batter, 3/4 cup for buttercream, and 1/2 cup for drizzle/assembly. Total yield ≈ 1 3/4 cups.

Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a bowl, whisk together 1 1/2 cups rolled oats, 3/4 cup flour, 3/4 tsp baking soda, 1 tsp cinnamon, and 1/4 tsp salt.

In a separate bowl, whisk melted 3/4 cup butter with 3/4 cup light brown sugar and 1/4 cup granulated sugar until smooth. Add 1 egg and 1 tsp vanilla and mix until combined.

Stir dry ingredients into wet until just combined. Drop tablespoons of dough 1 inch apart on prepared sheet and flatten slightly. Bake 10–12 minutes until edges are golden. Cool completely on a rack.

Once cool, coarsely chop cookies into small chunks (aim for 1/4–1/2-inch pieces). Reserve 1/2 cup for garnish and the rest (about 1 to 1 1/4 cups) to fold into cake filling.

Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment; set aside.

In a medium bowl whisk together 3 cups flour, 2 tsp baking powder, 1/2 tsp baking soda, and 3/4 tsp salt. Set aside.

In the bowl of a stand mixer fitted with the paddle (or using a large bowl and hand mixer), beat 1 cup room-temperature butter, 1 cup granulated sugar, and 3/4 cup packed light brown sugar on medium-high until pale and fluffy, about 3–4 minutes.

Add eggs one at a time, mixing 20–30 seconds after each addition. Mix in 2 tsp vanilla.

With mixer on low, add one-third of the dry ingredients, then half of 1 cup buttermilk, then another third of dry, then remaining buttermilk, finishing with the remaining dry — mix just until combined. Scrape bowl as needed.

Stir 1/2 cup cooled caramel sauce with 2 tbsp hot water to loosen, then gently fold into batter by hand until streaks of caramel are visible but batter is not fully homogeneous (this gives caramel ribbons).

Divide batter evenly between prepared pans and smooth. Bake 25–30 minutes until a toothpick inserted in center comes out with a few moist crumbs. Cool pans on a rack 10 minutes, then unmold cakes onto rack to cool completely before assembling.

With the mixer on medium speed, beat 1 1/2 cups very soft butter until smooth and slightly whipped, about 2 minutes.

Gradually add 5 cups sifted powdered sugar, 1 cup total, 1/2 cup, etc., pausing to scrape the bowl, mixing on low until incorporated to avoid clouds of sugar.

Add 3/4 cup cooled caramel sauce, 3 tbsp heavy cream, 1 tsp vanilla, and 1/2 tsp salt. Increase mixer speed to medium-high and beat 2–3 minutes until light, fluffy, and spreadable. Adjust consistency: add 1 tbsp cream if too thick or 1/2 cup more powdered sugar if too thin.

If cake layers have domes, level them with a serrated knife so they stack evenly.

Place one cake layer on a cake board or serving plate. Spread a thin crumb coat of buttercream (about 1/4–1/3 cup) to keep crumbs contained.

Spread 1/3 to 1/2 cup buttercream over the bottom layer to create the filling bed. Spread 1/3 cup caramel sauce over the buttercream, leaving a small margin to the edge.

Fold chopped oatmeal cookies (about 1 to 1 1/4 cups) lightly into 1/2 cup buttercream to create a chunky cookie filling. Spoon this cookie-buttercream mixture onto the bottom layer in an even layer (approximately 3/4 to 1 cup total), slightly mounded toward the center to compensate for the layer above.

Place second cake layer on top and press gently to adhere.

Crumb-coat the whole cake with a thin layer of buttercream and chill 20–30 minutes until set.

Apply a final coat of buttercream, smoothing with an offset spatula. Reserve some buttercream for dollops/decor if desired.

Warm remaining caramel sauce slightly if needed and drizzle decoratively over the top, allowing some to drip down the sides. Sprinkle reserved chopped cookies around the top edge or center, and finish with a light pinch of flaked sea salt if using.

Store the assembled cake loosely covered at room temperature for up to 1 day, or in the refrigerator for up to 4 days. If refrigerated, bring to room temperature 1–2 hours before serving for best texture; rewarm reserved caramel slightly before serving if chilled.