Preheat oven to 350℉.
Place the raspberries in a large bowl.
16 ounces raspberries
Add the sugar and cornstarch and stir to combine.
1/2 cup sugar, 1 tablespoon cornstarch
Dump the berries into the bottom of a baking dish (an 8x8-inch pan or deep pie plate) and spread to an even layer.
For the topping, start by combining the flour, sugar, and baking powder.
1 cup flour, 1/2 cup sugar, 1 teaspoon baking powder
Add the butter and use a fork or pastry cutter to cut the butter into small pieces (pea-sized or smaller).
1/4 cup salted butter
Drizzle the milk and vanilla on top, then stir to combine. Don't over-mix. It should look like a hybrid of sugar cookie dough and biscuit dough.
1/4 cup milk, 1 teaspoon vanilla extract
Break the topping apart to sprinkle evenly on top of the berry mixture.
Bake for 35-40 minutes or until golden brown on top and bubbly around the edges.
Serve warm with whipped topping or ice cream, if desired!