Crackly Chocolate Brownie Cookies

Preheat the oven. Heat to 350°F / 175°C. Line two baking sheets with parchment paper.

Melt the chocolate. Combine the chopped bittersweet chocolate and oil in a heatproof bowl. Melt gently in 20-second microwave intervals, stirring between each, or use a double boiler.

Cool slightly. Stir until completely smooth and glossy, then let stand for about 5 minutes. It should be warm, not piping hot.

Whip eggs and sugar. Beat the eggs and sugar on high speed for about 8-10 minutes.

Look for ribbon stage. The egg mixture should become much paler, thick, airy, and several times more voluminous. When the beaters are lifted, the mixture should fall in a thick ribbon that briefly sits on the surface.

Fold in chocolate. Pour the slightly cooled chocolate mixture into the whipped eggs and fold gently with a rubber spatula until mostly combined.

Add flour and salt. Sprinkle in the flour and salt and fold gently just until incorporated.

Add walnuts and chips. Fold in the walnuts and chocolate chips. Stop as soon as everything is evenly distributed.

The finished batter should be thick, glossy, and much looser than ordinary cookie dough. It is closer to brownie batter. Do not add extra flour.

Easiest method. Drop about 1 rounded Tbsp batter onto the parchment, leaving about 2 inches between cookies.

Prettiest method. Transfer batter to a piping bag with about a 3/4-inch / 2 cm opening and pipe small round mounds.

Do not flatten. Leave the mounds as they are; the batter will spread in the oven.

Work promptly. The batter thickens as the melted chocolate cools, so scoop or pipe soon after mixing.

Bake. Bake at 350°F / 175°C for 8-9 minutes.

Look for cracks. The tops should puff and develop a thin, shiny cracked crust.

Check the edges. Edges should look set while the centers still look soft.

Do not overbake. Do not wait for the centers to look dry; that would bake out the fudgy texture.

Cool on the tray. Leave the cookies on the baking sheet for about 5 minutes before moving them.

Transfer. Move carefully to a cooling rack. They will be fragile while very hot.