Preheat oven to 350°F (175°C). Melt ½ cup unsalted butter with 1 cup dark chocolate chips over low heat, stirring until smooth. Remove from heat and let cool slightly. Whisk in ¾ cup sugar, ½ teaspoon salt, 2 teaspoons vanilla extract, and 2 large eggs until just combined. Fold in ½ cup oat flour until cohesive.

Pour brownie batter into a greased 8-inch square pan and spread evenly. Bake for 35-38 minutes until a toothpick comes out clean. Cool in the pan for 1 hour.

Cut cooled brownies into ½ inch pieces and crumble into fine crumbs in a mixing bowl. Shape into 1.5-inch balls and place on a parchment-lined baking sheet.

Melt 1.5 cups of chocolate chips or candy melts in a microwave-safe bowl at 50% power, stirring every 30 seconds. Dip each brownie ball into the melted chocolate and allow excess to drip off.

While coating is still soft, sprinkle decorations over the truffles. Let them sit at room temperature until the chocolate has completely set.