Directions:

Muffins:
Preheat oven to 375 degrees F

Line a 12-cup standard muffin tin with paper liners.

Whisk baking powder, salt and two cups flour in a medium bowl and set aside.

Combine butter, sugar and lemon zest in a separate medium bowl.

Using an electric mixer, beat on medium speed until light and fluffy, about 4 minutes.

Add egg and beat to combine, scraping down sides of bowl as necessary.

With mixer on low, add flour in three additions, alternating with milk and ending with flour mixture. Beat to combine and scrape down sides of the bowl to be sure everything is incorporated.

Toss raspberries with remaining two teaspoons flour. Fold raspberries into batter and divide mixture evenly among muffin cups.

Crumb Topping:
Combine crushed potato chips, flour and sugar in a medium bowl.

Add melted butter and use a spatula to stir together until moist crumbs form.

Sprinkle crumbs evenly over muffins.

Bake until golden and a toothpick inserted in the center of the muffins comes out clean, 25 to 30 minutes. Let cool slightly. Serve warm or at room temperature.