In a medium saucepan, combine fresh raspberries, a sprinkle of sugar, and a splash of water. Cook over medium heat for about 5–7 minutes, stirring gently until the raspberries break down and the mixture becomes saucy. Once thickened, remove from heat and strain through a fine sieve to eliminate seeds.

In a separate saucepan, melt the semi-sweet chocolate chips and butter together over low heat. Stir continuously for around 5 minutes until smooth and glossy. Once melted, remove from heat and let cool for about 10 minutes.

While the chocolate and butter mixture cools, whisk together the eggs, sugar, and vanilla extract in a large mixing bowl for about 2–3 minutes until light and frothy.

Slowly pour the cooled chocolate mixture into the egg mixture, stirring continuously to avoid cooking the eggs for about 1 minute.

Gently fold in the all-purpose flour, salt, baking powder, and baking soda into the chocolate-egg mixture using a spatula for about 30 seconds.

Pour the brownie batter into a greased 8-inch baking dish, spreading it evenly with a spatula. Dollop spoonfuls of the raspberry sauce over the batter and swirl gently.

Preheat your oven to 350°F (175°C) and bake for about 30 minutes. Check for set edges with a slightly fudgy center.

Remove the brownies from the oven and allow to cool completely in the pan for at least 2 hours before slicing.