Preparation Combine butter, both sugars, and corn syrup in large bowl of stand mixer fitted with paddle attachment. Beat on medium-high speed until fluffy and pale, occasionally scraping down sides of bowl, about 3 minutes. Add eggs; beat on medium-high speed until mixture is very pale and sugar is completely dissolved, about 10 minutes. Add flour, baking powder, baking soda, and salt; beat on low speed just until blended, occasionally scraping down sides of bowl. Add Milk Crumbs; mix on low speed just until incorporated. Remove bowl from mixer. Stir in blueberries just until evenly distributed (dough will be very sticky). Using 1/4-cup ice cream scoop for each cookie, drop dough onto 2 large rimmed baking sheets. Cover with plastic wrap and refrigerate at least 24 hours. DO AHEAD: Can be made 2 days ahead. Keep chilled until baking time. Position 1 rack in top third and 1 rack in bottom third of oven and preheat to 375°F. Line 2 large (18x12-inch) rimmed baking sheets with parchment. Transfer 6 chilled dough scoops to each sheet, spacing at least 4 inches apart (cookies will spread). Bake cookies, 2 sheets at a time, until golden, reversing sheets halfway through baking, 20 to 22 minutes total. Repeat with remaining chilled dough, cooling and relining sheets between batches. Transfer cookies to racks; cool completely. DO AHEAD: Can be made 3 days ahead. Store in airtight containers at room temperature.
Preparation Combine butter, both sugars, and corn syrup in large bowl of stand mixer fitted with paddle attachment. Beat on medium-high speed until fluffy and pale, occasionally scraping down sides of bowl, about 3 minutes. Add eggs; beat on medium-high speed until mixture is very pale and sugar is completely dissolved, about 10 minutes. Add flour, baking powder, baking soda, and salt; beat on low speed just until blended, occasionally scraping down sides of bowl. Add Milk Crumbs; mix on low speed just until incorporated. Remove bowl from mixer. Stir in blueberries just until evenly distributed (dough will be very sticky). Using 1/4-cup ice cream scoop for each cookie, drop dough onto 2 large rimmed baking sheets. Cover with plastic wrap and refrigerate at least 24 hours. DO AHEAD: Can be made 2 days ahead. Keep chilled until baking time. Position 1 rack in top third and 1 rack in bottom third of oven and preheat to 375°F. Line 2 large (18x12-inch) rimmed baking sheets with parchment. Transfer 6 chilled dough scoops to each sheet, spacing at least 4 inches apart (cookies will spread). Bake cookies, 2 sheets at a time, until golden, reversing sheets halfway through baking, 20 to 22 minutes total. Repeat with remaining chilled dough, cooling and relining sheets between batches. Transfer cookies to racks; cool completely. DO AHEAD: Can be made 3 days ahead. Store in airtight containers at room temperature.