01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper, allowing overhang for easy removal.
02 - In a large bowl, beat softened butter and granulated sugar together until light and fluffy, approximately 2-3 minutes.
03 - Beat in eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract.
04 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt until evenly distributed.
05 - Gradually incorporate dry ingredients into wet mixture, stirring until just combined. Do not overmix.
06 - Press two-thirds of the dough evenly into the bottom of the prepared pan, creating a smooth, uniform layer.
07 - Spread strawberry jam evenly over the dough base, maintaining a small border around the edges.
08 - Crumble remaining dough over the jam layer. Press gently to adhere without compressing completely.
09 - Bake for 23-27 minutes until edges are golden brown and center is set. Remove from oven when done.
10 - Let bars cool completely in the pan on a wire rack before adding glaze, approximately 1 hour.
11 - Whisk powdered sugar, milk, and vanilla extract together until smooth and pourable. Add additional milk if needed for proper consistency.
12 - Drizzle glaze evenly over cooled bars. Immediately sprinkle with colorful sprinkles before glaze sets.
13 - Allow glaze to set for 15 minutes. Using parchment overhang, lift bars from pan and cut into 16 squares.