Peanut Cake (Peanut Brittle or Peanut Fudge)

Place the raw peanuts in a dry skillet over medium heat. Toast, stirring frequently, until they are fragrant and lightly browned, about 5 minutes. Watch them closely so they do not burn. Transfer to a plate to cool briefly.

Line a small baking tray (8x8 inches or similar) with parchment paper. The paper should extend over the edges for easy removal later.

In a heavy-bottomed saucepan, combine the brown sugar, water, ginger, cinnamon, and salt. Stir together over medium heat until the sugar dissolves, about 3 minutes. Then bring the mixture to a gentle boil. Insert a candy thermometer if you like: you want the syrup to reach about 260°F (hard-ball stage). If you don't have a thermometer, cook until the syrup thickens and large bubbles form.

Stir in the roasted peanuts and vanilla extract if using. Continue to cook for another 2-3 minutes, stirring constantly, as the mixture darkens and becomes very thick and sticky. The mixture will pull away from the sides of the pan slightly when ready.

Working quickly, scrape the hot peanut mixture into the prepared baking tray. Spread it evenly using a spatula or the back of a spoon. The candy will be thick and like a very stiff batter. Let it cool at room temperature for at least 15 minutes, until completely firm.

Using the parchment sling, lift the cooled peanut cake out of the tray. Place it on a cutting board. Using a sharp knife, cut into 16 squares or rectangles. The texture should be dense, slightly chewy, and fudge-like. If too hard, the candy was cooked too long; if too soft, cook a bit longer next time.