Step 1

Preheat the oven to 325 degrees F (163 degrees C).Lightly grease 2 baking sheets. Set aside.

Step 2

Combine semisweet chocolate, unsweetened chocolate chunks, and butter in a double boiler. Melt the chocolate over low heat until just melted, stirring occasionally. Be careful, not to burn the chocolate.

Step 3

Remove immediately. Stir to blend the butter and chocolate off the heat, and set aside.

Step 4

Combine the eggs, espresso powder, and vanilla extract in a large bowl and cream together using an electric mixer.

Step 5

Add the brown sugar and mix until creamy.In a separate bowl, sift together the flour, baking powder, and sea salt. Set aside.

Step 6

Add the melted chocolate and butter to the egg mixture and blend together using an electric mixture. Then add the flour mixture and stir by hand just until the dry ingredients and are moist.

Step 7

Add the chopped nuts and the chocolate chips to the chocolate and flour mixture folding them in gently. Note: The dough will be relatively soft.Drop by large tablespoonfuls onto the greased baking sheets at least 3 inches apart. If you want your cookies to look uniform in size then use a 2 oz. cookie or ice cream scoop.

Step 8

Bake immediately to prevent the chocolate from hardening for 10 to 12 minutes. Rotate the pan halfway through the baking time. The cookies will still be very soft and sticky inside, but do not overcook the cookies or they will be crispy, rather than chewy. Cool for 10 minutes on the baking sheets before gently removing the whoppers to a baking rack to cool completely.Store the cookies in an airtight container separating the layers with wax paper.Makes about 1 dozen 3-inch cookies