From 6 Bittersweets
Adapted from Martha Stewart
Makes about 2 dozen cookies
8 ounces semisweet chocolate, roughly chopped
4 Tbsp (1/2 stick) unsalted butter
2/3 cup all purpose flour [spooned and leveled to measure]
1/2 tsp baking powder
1/3 tsp salt
2 large eggs, room temperature
1/2 cup PLUS 2 Tbsp packed light brown sugar
1 tsp pure vanilla extract
1 cup butterscotch chips
Preheat oven to 350 degrees F. Line 1 or 2 baking sheets with parchment paper or silicon baking mats, if you have them. Heat chopped chocolate and butter in a microwave-safe bowl in 20-second intervals, stirring in between, until almost melted; do not overheat since chocolate burns easily. In another bowl, whisk together flour, baking powder, and salt.
In a large mixing bowl, beat eggs, brown sugar, and vanilla on high speed until light and fluffy. Reduce speed to low; beat in melted chocolate. Mix in flour mixture until just combined. Stir in butterscotch chips. Refrigerate the dough for about 15 minutes.
Drop heaping tablespoons of dough 2 to 3 inches apart onto baking sheets. Bake, rotating sheets halfway through, until cookies are shiny and crackly yet soft in centers, about 11 to 15 minutes total. (Do NOT overbake these, as these cookies can easily become dry.) Cool on sheets 10 minutes; with a thin spatula, carefully transfer cookies to wire racks to cool completely.