Flutter Button Placed Below GridView Builder

I want to have a big long button below the Gridview just like the logout button in the Roblox app

I manage to create a gridview and button using the Column , however the button is floating above the gridview, how to make it placed nicely below the gridview without floating above the gridview?

Here is my code

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final title = 'Grid List';

    return MaterialApp(
      title: title,
      home: Scaffold(
        appBar: AppBar(
          title: Text(title),
        ),
        body: MainMenuBody(),
      ),
    );
  }
}

class MainMenuBody extends StatelessWidget {

  @override
  Widget build(BuildContext context) {

    final List<MenuData> menu = [
      MenuData(Icons.move_to_inbox_outlined, 'Menu 1'),
      MenuData(Icons.find_in_page_outlined, 'Menu 2'),
      MenuData(Icons.find_in_page_outlined, 'Menu 3'),
      MenuData(Icons.upgrade_outlined, 'Menu 4'),
      MenuData(Icons.upgrade_outlined, 'Menu 5'),
      MenuData(Icons.play_for_work_outlined, 'Menu 6'),
      MenuData(Icons.play_for_work_outlined, 'Menu 7'),
      MenuData(Icons.assignment_turned_in_outlined, 'Menu 8'),
      MenuData(Icons.assignment_turned_in_outlined, 'Menu 9'),
      MenuData(Icons.fact_check_outlined, 'Menu 10')
    ];

    return Container(
    child: Scrollbar(
  thickness: 3,
  child: Padding(
    padding: EdgeInsets.symmetric(horizontal: 10.0),
    child: SingleChildScrollView(
      child: Column(
        children: [
          GridView.builder(
            shrinkWrap: true,
            physics: BouncingScrollPhysics(),
            itemCount: menu.length,
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                childAspectRatio: 1,
                crossAxisCount: 2,
                crossAxisSpacing: 4.0,
                mainAxisSpacing: 4.0),
            itemBuilder: (BuildContext context, int index) {
              return Card(
                elevation: 0.2,
                shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8.0)),
                child: InkWell(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Icon(
                        menu[index].icon,
                        size: 30,
                      ),
                      SizedBox(height: 20),
                      Text(
                        menu[index].title,
                        textAlign: TextAlign.center,
                        style: TextStyle(
                            fontSize: 10,
                            color: Colors.black87),
                      )
                    ],
                  ),
                ),
              );
            },
          ),
          Center(
            child: RaisedButton(
              child: Text("Button"),
              onPressed: (){},
            ),
          ),
        ],
      ),
    ),
  ),
));
  }
}

class MenuData {
  MenuData(this.icon, this.title);
  final IconData icon;
  final String title;
}

I have modified your code a little bit. Please have a look.

Wrap the column inside a SingleChildScrollView, Remove Expanded widget and add shrinkWrap: true inside GridView

return Container(
    child: Scrollbar(
  thickness: 3,
  child: Padding(
    padding: EdgeInsets.symmetric(horizontal: 10.0),
    child: SingleChildScrollView(
      physics: BouncingScrollPhysics(),
      child: Column(
        children: [
          GridView.builder(
            shrinkWrap: true,
            physics: BouncingScrollPhysics(),
            itemCount: menu.length,
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                childAspectRatio: 1,
                crossAxisCount: 2,
                crossAxisSpacing: 4.0,
                mainAxisSpacing: 4.0),
            itemBuilder: (BuildContext context, int index) {
              return Card(
                elevation: 0.2,
                shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8.0)),
                child: InkWell(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Icon(
                        menu[index].icon,
                        size: 30,
                      ),
                      SizedBox(height: 20),
                      Text(
                        menu[index].title,
                        textAlign: TextAlign.center,
                        style: TextStyle(
                            fontSize: 10,
                            color: Colors.black87),
                      )
                    ],
                  ),
                ),
              );
            },
          ),
          Center(
            child: RaisedButton(
              child: Text("Button"),
              onPressed: (){},
            ),
          ),
        ],
      ),
    ),
  ),
));