Adjust oven rack to middle position and heat to 350°F. Spray muffin tin with cooking spray, making sure to spray the edges around the cups as well.
Spread fennel seeds onto sheet pan and toast in oven for 10 minutes until lightly toasted and fragrant.
Remove pan from oven, transfer seeds to a small bowl and allow to cool. When seeds have cooled, measure out 1 tablespoon and set aside. Transfer remaining seeds to a spice grinder and process until it is finely ground. Measure out 2 teaspoons and add to fennel seeds.
In a medium bowl whisk together egg, egg white and brown sugar until pale in color. Set aside and allow to sit for 5 minutes until mixture becomes foamy.
In a small bowl mix together shredded pear, zest, lemon juice and cranberries.
Add vanilla, yogurt, oil, fennel seeds, ground fennel and shredded pear mixture to liquid ingredients. Mix until combined.
In a large bowl whisk together flour, baking powder, baking soda and salt. Form a well in the dry ingredients and add wet ingredients. Mix, folding until just combined and no dry flour is visible.
Spoon batter into cups and fill to top. Sprinkle tops of muffin with turbinado sugar and transfer pan to oven. Bake for 18–20 minutes or until tops of muffins spring back when lightly touched.
Remove from oven and allow muffins to cool in the pan for 5 minutes. Serve warm or transfer to wire rack to completely cool before storing in an air-tight container. Can be stored for up to three days.