01 - Preheat the oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or lightly grease each cavity.
02 - In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, baking soda, and salt until thoroughly blended.
03 - In a separate bowl, whisk the ricotta cheese, eggs, milk, vegetable oil, and vanilla extract until the mixture is smooth and cohesive.
04 - Introduce the wet mixture to the dry ingredients. Stir gently with a spatula until just combined, ensuring not to overmix.
05 - Carefully fold in 3/4 cup of the chopped walnuts, reserving the remaining portion for garnish.
06 - Distribute the batter evenly among all muffin cups. Top each portion with the reserved walnuts and a sprinkle of demerara or turbinado sugar.
07 - Place the tray in the oven and bake for 18 to 22 minutes, or until the muffins are golden brown and a toothpick inserted into the center emerges clean.
08 - Allow muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool thoroughly before serving.