Step 1: Warm the milk in a small saucepan or microwave until it reaches 105-115°F (40-46°C). Pour into a large bowl, then sprinkle in the active dry yeast and 1 teaspoon of granulated sugar. Stir gently and let it sit for 5-10 minutes until foamy. This confirms your yeast is active.
Step 2: In a separate bowl, whisk together the remaining granulated sugar, melted butter, eggs, and vanilla extract. Add this mixture to the yeast mixture and stir until well combined.
Step 3: Gradually add the all-purpose flour and salt to the wet ingredients, mixing with a wooden spoon or stand mixer with a dough hook attachment. Once the dough comes together, knead for 5-7 minutes (by hand) or 3-5 minutes (with a mixer) until smooth and elastic. The dough for your Raspberry Filled Donuts should be slightly tacky but not overly sticky.
Step 4: Lightly grease a large bowl with vegetable oil. Place the dough in the bowl, turning once to coat. Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place for 1-1.5 hours, or until doubled in size.
Step 5: Once the dough has risen, gently punch it down to release the air. On a lightly floured surface, roll out the dough to about 1/2 inch thickness. Use a 2-3 inch round cookie cutter or glass to cut out donut rounds. You can gather and re-roll scraps, but the second batch of donuts might not be as light.
Step 6: Place the cut donut rounds on parchment-lined baking sheets, leaving some space between them. Cover loosely with plastic wrap or a towel and let them rise again for 30-45 minutes, or until noticeably puffy. This second rise is crucial for light Raspberry Filled Donuts.
Step 7: While the donuts are rising, heat about 2-3 inches of vegetable oil in a large heavy-bottomed pot or Dutch oven to 350°F (175°C). Use a candy thermometer to monitor the temperature; it’s vital for perfectly cooked donuts.
Step 8: Carefully drop 2-3 donuts into the hot oil at a time, being careful not to overcrowd the pot. Fry for 1-2 minutes per side, until golden brown. Use a slotted spoon or spider to flip them.
Step 9: Remove the fried donuts from the oil and place them on a wire rack lined with paper towels to drain excess oil. While still warm, you can roll them in granulated sugar or powdered sugar for a classic finish.
Step 10: Once the Raspberry Filled Donuts have cooled slightly (warm, not hot), prepare your filling. If using preserves, transfer to a piping bag fitted with a long, thin tip (like a Bismark tip). If making compote, ensure it’s cooled. Insert the tip into the side of each donut and gently squeeze to fill. You’ll feel the donut plump up slightly.
Step 11: Dust generously with powdered sugar just before serving. Enjoy your homemade Raspberry Filled Donuts!