Preheat oven to 400°F. Toss the pears with the melted butter and a pinch of sea salt. Spread the pears on a baking sheet and roast for 12–15 minutes, until the pears soften slightly. Let cool. 

Reduce oven temperature to 350°F. Grease a 9x5x3 inch baking pan with cooking spray or butter.

Place ½ cup softened butter in a large bowl. Mix on high with a hand mixer until fluffy. Add 1 cup sugar and continue beating until pale yellow and fluffy. Slowly beat in the eggs.

In a medium bowl, whisk together the 2 cups flour, baking soda, and salt. Add half of the flour mixture to the butter mixture, beat on low until just combined. Add half the milk and beat until combined. Repeat with the remaining flour mixture and remaining milk.

Stir in the roasted pears and candied ginger. 

In a medium bowl, whisk together the flour, brown sugar, a ginger. Dice the butter into small cubes, and add the cubes to the flour mixture. Use your fingers to incorporate the butter into the flour mixture, squishing the butter between your fingers. Stop when the butter reaches pea-size pieces.

Spread the batter into the greased pan. Sprinkle with the streusel. Pat down lightly. 

Bake for 55–65 minutes, or until golden brown and a toothpick comes out clean. Check the loaf around 40 minutes—if the top looks golden brown, loosely place a piece of aluminum foil on top for the rest of the baking time.

Remove from the oven and run a knife along the edges of the pan. Let cool at least 15 minutes before removing from the pan.