Step 1

Preheat the oven to 350°F (175°C). Line the bottom and sides of a 9-inch (23-cm) springform pan by cutting out a circle of parchment paper for the bottom and a long strip for the sides, spraying a bit of nonstick spray underneath the paper to stick it to the pan. Set aside.

Step 2

In a microwave-safe bowl, combine the chocolate and butter and microwave on a medium setting, stirring every 20 seconds, for 1 to 2 minutes, or until the chocolate is completely melted and combined with the butter.

Step 3

Transfer the chocolate mixture to a large bowl. Add the sugar, vanilla, and salt and whisk just to combine, about 1 minute. Then, whisk in the eggs just until combined, about 1 minute. Sift in the cocoa powder and whisk just to incorporate, about 1 minute.

Step 4

Pour the batter into the prepared baking pan and bake for 25 to 30 minutes or until a toothpick inserted into the center comes out clean with a few moist crumbs attached.

Step 5

Remove from the oven and let the cake cool for about 15 minutes. Serve the cake either warm and fresh with some whipped cream, ice cream, or fruits or cold with a bit of powdered sugar. Store in an airtight container at room temperature for up to 5 days. Reheat leftover cake slices in the microwave, if desired. Freeze for up to 3 months.