Position the oven rack in the center position and preheat the oven to 400°F Prepare the muffin pans by spraying the cups and their rims with nonstick spray, or by placing the paper cups inside. If using silicon muffin pans, spray as directed and place on a cookie sheet.
Place the pine nuts on a baking sheet and bake for 6 minutes, stirring occasionally, until lightly brown and fragrant. Transfer the nuts to a large plate and cool for 10 minutes. Leave the oven on and at the same temperature.
Pour 1/3 cup of the toasted nuts into a food processor, a mini food processor, or a blender; pulse 5 or 6 times until the nuts are finely ground. *Be careful not to grind them to a paste.* Transfer the ground nuts to a medium bowl. Stir in the flour, sugar, baking powder, salt and the remaining pine nuts until well combined.
Whisk the eggs and ricotta in a large bowl, then whisk in the milk, oil and vanilla until smooth. Use a wooden spoon to stir in the prepared flour mixture until moistened. Make sure the pine nuts are evenly distributed in the batter, but do not over mix.
Fill the prepared tins three-quarters full. Save the leftover batter for a second baking. Bake for 22 minutes, or until the muffins are pale brown with rounded, cracked tops. A toothpick inserted into one of the muffins should come out with a few moist crumbs attached.
Set the pan on a wire rack to cool for 10 minutes. Gently rock each muffin back and forth to release and remove it from the pan. Cool them for 5 minnutes more before serving. If storing or freezing the muffins, cool completely before putting into air tight containers or freezer bags. These muffins will stay fresh for up to 24 hours at room temperature or up to 1 month in the freezer.