Preheat the oven to 350°F (175°C) and prepare your baking pan with parchment paper and cooking spray.

In a heavy-bottomed saucepan over low heat, melt the unsalted butter until fully liquefied.

Stir in the granulated sugar until the mixture is smooth, then remove from heat and let cool for 5 minutes, stirring frequently.

Add the canola oil and vanilla extract, stirring until fully combined.

Beat in the eggs one at a time, ensuring each is fully mixed in before adding the next.

Sift together the all-purpose flour, cocoa powder, malted milk powder (if using), and salt directly into the chocolate mixture.

Gently fold the mini chocolate chips into the batter until evenly distributed.

Pour the brownie batter into the prepared pan and bake for 25-30 minutes (9x13-inch pan) or 40-45 minutes (8x8 or 9x9-inch pan).

Allow the brownies to cool in the pan before slicing into squares for serving.