Preheat the oven at 175°C conventional oven.
Prep a 20x20 square pan with parchment paper.
Melt the butter, and pour the melted butter into a mixing bowl. Add the brown sugar, granulated sugar and vanilla extract. Use a hand whisk and mix until combined, for about 30-60 seconds.
150 g butter, 150 g granulated sugar, 50 g brown sugar, 1 teaspoon vanilla extract
Add the eggs one at a time, and mix until incorporated. Once incorporated, continue giving them a good whisk for 1-2 minutes. You will also see, when you whisked enough that it will start to come together in a smooth batter.
2 large egg
In a separate bowl mix together the flour, funfetti sprinkles and salt.
150 g all-purpose flour, 3 tablespoon funfetti sprinkles, Pinch of salt
Add it to the wet batter and gently mix the batter together until just combined.
Pour the batter into your baking pan and even it out with the spatula.
Bake for about 20-22 min. Once baked place it on a cooling rack and let it cool down.