In a mixing bowl, whisk together 2 cups of all-purpose flour, ½ cup of Dutch-processed cocoa powder, 1 teaspoon of baking powder, ½ teaspoon of baking soda, and ½ teaspoon of salt. Set it aside.

In a stand mixer, combine 1 cup of softened unsalted butter, ½ cup of light brown sugar, and ½ cup of granulated sugar. Beat for 3 to 4 minutes. Then add in 1 large egg, 1 egg yolk, 1 teaspoon of vanilla extract, and 2 tablespoons of vegetable oil, mixing well.

Gradually add the dry ingredients to the wet ingredients. Mix on low speed just until combined. Wrap the dough in plastic wrap and refrigerate for a minimum of 5 hours.

Preheat the oven to 350°F (180°C) and line baking sheets with parchment paper.

Scoop out 10-gram portions of dough and roll them into balls. Roll each ball in turbinado sugar, then chill in the freezer for about 15 minutes.

Arrange the dough balls on the prepared baking sheets and bake for 7 to 8 minutes. Allow to cool on the baking sheet for 5 minutes before transferring to wire racks.

To make the salted caramel filling, heat 1 cup of granulated sugar in a saucepan, stirring until melted and amber. Remove from heat, whisk in 6 tablespoons of unsalted butter and ½ cup of heavy cream until smooth, then stir in a pinch of salt.

Take one cooled chocolate cookie, spread about 1 teaspoon of salted caramel filling on the flat side, and top with another cookie. Repeat until all cookies are filled.