1/2 stick unsalted butter or margarine
3/4 cup packed light brown sugar
2 egg yolks
1 tsp vanilla
8 oz bittersweet chocolate, melted
1/2 cup matzo meal
1/4 tsp Kosher salt
4 egg whites
8 oz semisweet chocolate chips
Preheat oven to 350. Beat butter and sugar together until fluffy. Beat in yolks and vanilla. Add chocolate, matzo meal, and salt. Beat until combined but still thick.
Beat egg whites until stiff peaks form. Gently fold into chocolate mixture. Add chocolate chips. Let sit 15 minutes.
Scoop 2-inch balls onto baking sheet lined with parchment. Bake 10-12 minutes. Cool 2 minutes then transfer to cooling rack.