Preheat the oven to 350°F (175°C). Grease or line an 8x8-inch baking pan with parchment paper, leaving an overhang for easy removal.

In a mixing bowl, whisk together melted butter and granulated sugar until combined and glossy.

Add the eggs and vanilla extract, whisking until the mixture is thick and slightly lightened in color.

Sift in cocoa powder, flour, salt, and baking powder. Stir gently with a spatula just until no dry streaks remain; do not overmix.

Spread the batter evenly into the prepared pan and smooth the top.

Bake for 20–25 minutes, or until a toothpick inserted near the center comes out with moist crumbs but not wet batter.

Cool completely in the pan on a wire rack. Once cooled, lift the brownies out using the parchment overhang.

Using a small heart-shaped cookie cutter, cut heart shapes from the cooled brownie slab. Gently press to release each heart; save scraps for snacking or crumbling over ice cream.

Place the brownie hearts on a parchment-lined baking sheet and chill in the refrigerator for 15–20 minutes to firm up.

In a microwave-safe bowl, combine chocolate chips and oil. Microwave in 20–30 second bursts, stirring between each, until smooth and fully melted.

Dip each chilled brownie heart halfway or fully into the melted chocolate, letting excess drip back into the bowl.

Set dipped brownies back on the parchment-lined sheet and immediately add sprinkles or crushed candies if using.

Refrigerate for 15–20 minutes, or until the chocolate is set. Serve at room temperature.