Preheat the oven to 325˚ F. Line a few sheet pans with parchment paper. When oven is preheated, place pecans in a small pan and toast for 10 minutes or until crisp and golden. Set aside to cool while making batter.

Place the butter, 6 ounces of the chocolate chips, and the unsweetened chocolate, in a microwave-safe bowl. Heat on high for 1 minute, remove from microwave and stir. Heat for another 30 seconds, then stir again. Repeat until mixture is just melted. Cool for 15 minutes.

In the bowl of an electric mixer fitted with the paddle attachment, beat the eggs and vanilla until combined. Add the sugar, raise the speed to medium-high, and beat for 2 more minutes, until the batter is thick and falls back on itself in a ribbon. Set aside.

With the mixer on low, slowly add the chocolate mixture to the egg mixture. Combine the flour, baking powder, and salt in a small bowl and fold it into the chocolate mixture with a rubber spatula.

In another bowl, combine the pecans, peanut butter chips, the remaining 6 ounces of chocolate chips, and the toffee bits and fold it into the chocolate mixture. Scoop rounded mounds of batter 1 inch apart onto the prepared sheet pans.

Bake for 13-15 minutes. (I like to under bake them slightly, so that they're soft and chocolatey in the centers and crisp on the outsides. Cool on the baking sheets.