In a bowl, combine butter & sugar, beat until light & fluffy. Mix in flour & baking powder; blend together. Chill dough for about 30 minutes.
Preheat oven to 375 F.
Pat into a 14 X 4-inch baking pan. Bake until golden about 10-12 minutes. Remove from oven & cool.
Glaze
In a small pot, combine all glaze ingredients & stir well. Bring to a boil then turn the heat down & gently simmer for about 5 minutes. Remove from heat & allow to cool.
Blueberry Cream
Whip cream with sugar & blueberry emulsion until it forms stiff peaks. Place in a pastry bag with a star tip. Place in refrigerator until ready to use.
Assembly
Spread lime curd evenly over bottom of pastry then slice into 8 ‘bars’. (I like to slice it at this point rather than after it is filled with blueberries so it presents a ‘cleaner’ cut look).
Gently fold fresh blueberries into the glaze. Cover each bar with about 3 rows of glazed blueberries.
Top the blueberries with a generous swirl of blueberry cream & sprinkle with lime zest.