In a large bowl add all purpose flour, baking powder, ginger and salt and mix well .
In another bowl , beat butter, brown sugar, and ¼ cup granulated sugar until fluffy, about 2 minutes. Add peanut butter and beat until combined.
Add egg and vanilla and beat until combined. Reduce speed to low, add flour mixture in 2 additions, and mix until just combined. Cover bowl tightly with plastic wrap and refrigerate for 30 minutes.
Adjust oven rack to middle position and heat oven to 350 F. Line the baking sheet with parchment paper. Roll dough into 1-inch balls . Roll them into ¼ cup granulated sugar and space them 2 inches apart on prepared sheets.
Bake, 1 sheet at a time, until cookies are just set and beginning to crack, 9 to 11 minutes. Working quickly, remove sheet from oven and place 1 candy in center of each cookie, pressing down firmly.
Return sheet back to the oven and bake until cookies are light golden, about 2 minutes longer. Let cookies cool on sheet for 5 minutes, then transfer to wire rack. Let cookies cool completely before serving.