📖 Instructions

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). This ensures that the cake bakes evenly.
2. Grease and Flour the Cake Pan: Thoroughly grease a 9-inch round cake pan with butter or cooking spray. Dust the pan with flour, tapping out any excess. This prevents the cake from sticking to the pan. I forgot to do this one time, and... I don't want to talk about it.
3. Prepare the Rhubarb: Wash and trim 1 pound of rhubarb stalks. Cut them into ½-inch pieces. Set aside. It's important to get the pieces roughly the same size so they cook evenly.
4. Prepare the Raspberries: Gently rinse 1 ½ cups of fresh raspberries. Pat them dry with a paper towel to remove excess moisture. This will prevent them from sinking to the bottom of the cake.
5. Cream Butter and Sugar: In a large mixing bowl, cream together 1 cup (2 sticks) of unsalted butter, softened, and 1 ¾ cups of granulated sugar until light and fluffy. This usually takes about 3-5 minutes with an electric mixer.
6. Add Eggs and Vanilla: Beat in 2 large eggs, one at a time, then stir in 1 teaspoon of vanilla extract. Make sure each egg is fully incorporated before adding the next. If the mixture looks curdled, don't panic! It'll come together when you add the dry ingredients. I usually add a tablespoon of flour and mix until it's smooth.
7. Combine Dry Ingredients: In a separate bowl, whisk together 3 cups of all-purpose flour, 1 teaspoon of baking powder, and ½ teaspoon of baking soda, and ¼ tsp of salt. Whisking ensures that the baking powder and baking soda are evenly distributed throughout the flour.
8. Alternate Wet and Dry Ingredients: Gradually add the dry ingredients to the wet ingredients, alternating with 1 cup of buttermilk, beginning and ending with the dry ingredients. Mix until just combined. Be careful not to overmix the batter. Overmixing can result in a tough cake.
9. Fold in Rhubarb and Raspberries: Gently fold in the chopped rhubarb and raspberries into the batter. Distribute them evenly throughout the batter.
10. Pour Batter into Pan: Pour the batter into the prepared cake pan and spread evenly. I like to give the pan a gentle tap on the counter to release any air bubbles.
11. Bake the Cake: Bake in the preheated oven for 50-60 minutes, or until a wooden skewer inserted into the center comes out clean. Start checking for doneness around 50 minutes. Ovens can vary, so it’s better to be safe than sorry. I find it helpful to place a tent of foil over the cake if it starts browning too quickly.
12. Cool the Cake: Let the cake cool in the pan for 10-15 minutes before inverting it onto a wire rack to cool completely. Cooling the cake in the pan helps it retain its moisture and prevents it from breaking apart when you invert it.
13. Make the Crumb Topping (Optional): In a small bowl, combine ½ cup of all-purpose flour, ¼ cup of granulated sugar, ¼ cup of packed brown sugar, and ¼ cup (½ stick) of cold unsalted butter, cut into small pieces. Use a pastry blender or your fingers to cut the butter into the flour mixture until it resembles coarse crumbs. Sprinkle the crumb topping over the cake batter before baking, if desired. I sometimes add chopped walnuts or pecans to the crumb topping for extra flavor and crunch.
14. Make the Glaze (Optional): In a small bowl, whisk together 1 cup of powdered sugar and 2-3 tablespoons of milk or lemon juice until smooth. Drizzle the glaze over the cooled cake. I love adding a bit of lemon zest to the glaze for a bright, citrusy flavor.