1½ sticks unsalted butter, melted, plus more for greasing insert
1½ cups sugar
⅔ cup unsweetened cocoa powder
⅓ cup all-purpose flour
3 large eggs, lightly beaten
1 teaspoon pure vanilla extract
Kosher salt
½ cup semisweet chocolate chunks
Vanilla ice cream, for serving
Instructions
Line the insert of a 4- or 6-quart slow cooker with a large piece of foil, then generously butter the foil.
Whisk together the melted butter, sugar, cocoa powder, flour, eggs, vanilla and ½ teaspoon salt in a medium bowl. Fold in the chocolate chunks. Scrape the batter out into the prepared insert in an even layer. Cover and cook on low for 3 hours; the cake should be set around the edges and gooey in the center.
Serve the cake warm, scooped into a bowl and topped with ice cream.
Recipe by Big City Tiny Kitchen at https://bigcitytinykitchen.com/slow-cooker-brownie-cake/